diff --git a/src/common.h b/src/common.h
index a06518d2..4845f096 100644
--- a/src/common.h
+++ b/src/common.h
@@ -514,15 +514,6 @@ INLINE i64 clamp_i64(i64 v, i64 min, i64 max) { return v < min ? min : v > max ?
 INLINE f32 clamp_f32(f32 v, f32 min, f32 max) { return v < min ? min : v > max ? max : v; }
 INLINE f64 clamp_f64(f64 v, f64 min, f64 max) { return v < min ? min : v > max ? max : v; }
 
-INLINE u64 cstr_len(char *cstr)
-{
-    u64 len = 0;
-    for (char *c = cstr; *c != 0; ++c) {
-        ++len;
-    }
-    return len;
-}
-
 /* ========================== *
  * Profiling
  * ========================== */
diff --git a/src/font.c b/src/font.c
index 8968062b..b815536a 100644
--- a/src/font.c
+++ b/src/font.c
@@ -186,7 +186,7 @@ struct asset *font_load_asset(struct string path, f32 point_size, b32 help)
                                     STR("Font path \"%F\" too long!"),
                                     FMT_STR(path)));
         }
-        string_to_cstr_buff(path, BUFFER_FROM_ARRAY(params->path_cstr));
+        cstr_buff_from_string(BUFFER_FROM_ARRAY(params->path_cstr), path);
         params->path_len = path.len;
         params->asset = asset;
         params->point_size = point_size;
diff --git a/src/resource.h b/src/resource.h
index 599cdaf8..6ef34aa9 100644
--- a/src/resource.h
+++ b/src/resource.h
@@ -8,6 +8,7 @@
 struct resource {
     struct buffer bytes;
 
+    /* Internal */
 #if !RESOURCES_EMBEDDED
     struct sys_file file;
     struct sys_file_map file_map;
diff --git a/src/sheet.c b/src/sheet.c
index 3603b4e3..8b880a4b 100644
--- a/src/sheet.c
+++ b/src/sheet.c
@@ -236,7 +236,7 @@ struct asset *sheet_load_asset(struct string path, b32 help)
                                     STR("Sheet path \"%F\" too long!"),
                                     FMT_STR(path)));
         }
-        string_to_cstr_buff(path, BUFFER_FROM_ARRAY(params->path_cstr));
+        cstr_buff_from_string(BUFFER_FROM_ARRAY(params->path_cstr), path);
         params->path_len = path.len;
         params->asset = asset;
 
diff --git a/src/sound.c b/src/sound.c
index de6728a7..f97624fd 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -191,7 +191,7 @@ struct asset *sound_load_asset(struct string path, u32 flags, b32 help)
                                     STR("Sound path \"%F\" too long!"),
                                     FMT_STR(path)));
         }
-        string_to_cstr_buff(path, BUFFER_FROM_ARRAY(params->path_cstr));
+        cstr_buff_from_string(BUFFER_FROM_ARRAY(params->path_cstr), path);
         params->path_len = path.len;
         params->asset = asset;
         params->flags = flags;
diff --git a/src/string.c b/src/string.c
index e964f06f..d7b5ac91 100644
--- a/src/string.c
+++ b/src/string.c
@@ -160,54 +160,17 @@ struct string string_copy(struct arena *arena, struct string src)
     return str;
 }
 
-struct string string_copy_buff(struct buffer buff, struct string src)
+struct string string_copy_buff(struct buffer dest_buff, struct string src)
 {
-    u64 len = min_u64(buff.size, src.len);
+    u64 len = min_u64(dest_buff.size, src.len);
     struct string str = {
         .len = len,
-        .text = buff.data
+        .text = dest_buff.data
     };
     MEMCPY(str.text, src.text, src.len);
     return str;
 }
 
-/* TODO: Benchmark performance of appending each character while calculating size here */
-// //struct string string_copy_cstr(struct arena *arena, char *cstr)
-// //{
-// //    u8 *final_text = arena_next(arena);
-// //    char *c = cstr;
-// //    for (; *c != 0; ++c) {
-// //        u8 *new_char = arena_push(arena, 1);
-// //        *new_char = *c;
-// //    }
-// //    return (struct string) {
-// //        .len = c - cstr,
-// //        .text = final_text
-// //    };
-// //}
-
-struct string string_from_cstr(char *cstr)
-{
-    struct string str = { 0 };
-    if (cstr) {
-        char *c = cstr;
-        while (*c != 0) {
-            ++c;
-        }
-        str.len = c - cstr;
-        str.text = (u8 *)cstr;
-    }
-    return str;
-}
-
-struct string string_from_cstr_len(char *cstr, u64 len)
-{
-    return (struct string) {
-        .text = (u8 *)cstr,
-        .len = len
-    };
-}
-
 struct string string_repeat(struct arena *arena, struct string src, u64 count)
 {
     u64 final_len = src.len * count;
@@ -365,54 +328,6 @@ b32 string_ends_with(struct string str, struct string substring)
     return false;
 }
 
-#if 0
-/* NOTE: This is a LOSSY conversion.
- * `wstr` must be null-terminated.
- */
-struct string string_from_wstr(struct arena *arena, u16 *wstr)
-{
-    u8 *final_text = arena_next(arena);
-    u16 *wchar = wstr;
-    for (; *wchar != 0; ++wchar) {
-        u8 *c = arena_push(arena, 1);
-        *c = (u8)(*wchar & 0xFF);
-    }
-    return (struct string) {
-        .len = wchar - wstr,
-        .text = final_text
-    };
-}
-#endif
-
-char *string_to_cstr(struct arena *arena, struct string str)
-{
-    u8 *text = arena_push_array(arena, u8, str.len + 1);
-    MEMCPY(text, str.text, str.len);
-    text[str.len] = '\0';
-    return (char *)text;
-}
-
-char *string_to_cstr_buff(struct string str, struct buffer buff)
-{
-    if (buff.size > 0) {
-        u64 len = min_u64(str.len, buff.size - 1);
-        MEMCPY(buff.data, str.text, len);
-        buff.data[len] = '\0';
-    }
-    return (char *)buff.data;
-}
-
-wchar_t *string_to_wstr(struct arena *arena, struct string str)
-{
-    /* FIXME: Do proper encoding. */
-    u16 *text = arena_push_array(arena, u16, str.len + 1);
-    for (u64 i = 0; i < str.len; ++i) {
-        text[i] = (u16)str.text[i];
-    }
-    text[str.len] = '\0';
-    return (wchar_t *)text;
-}
-
 /* ========================== *
  * Format
  * ========================== */
@@ -549,7 +464,7 @@ struct string _string_format(struct arena *arena, struct string fmt, ...)
 }
 
 /* ========================== *
- * Unicode transformation
+ * Unicode
  * ========================== */
 
 /* utf8 <- utf16 */
@@ -576,6 +491,30 @@ struct string string_from_string16(struct arena *arena, struct string16 str16)
     return res;
 }
 
+/* utf8 <- utf32 */
+struct string string_from_string32(struct arena *arena, struct string32 str32)
+{
+    struct string res = {
+        .len = 0,
+        .text = arena_dry_push(arena, u8)
+    };
+
+    u64 pos32 = 0;
+    while (pos32 < str32.len) {
+        struct string32 str32_remaining = { .len = (str32.len - pos32), .text = str32.text + pos32 };
+        struct utf32_decode_result decoded = utf32_decode(str32_remaining);
+        struct utf8_encode_result encoded = utf8_encode(decoded.codepoint);
+
+        u8 *dest = arena_push_array(arena, u8, encoded.count8);
+        MEMCPY(dest, &encoded.chars8, encoded.count8);
+
+        pos32 += 1;
+        res.len += encoded.count8;
+    }
+
+    return res;
+}
+
 /* utf16 <- utf8 */
 struct string16 string16_from_string(struct arena *arena, struct string str8)
 {
@@ -600,30 +539,6 @@ struct string16 string16_from_string(struct arena *arena, struct string str8)
     return res;
 }
 
-/* utf8 <- utf32 */
-struct string string_from_string32(struct arena *arena, struct string32 str32)
-{
-    struct string res = {
-        .len = 0,
-        .text = arena_dry_push(arena, u8)
-    };
-
-    u64 pos32 = 0;
-    while (pos32 < str32.len) {
-        struct string32 str32_remaining = { .len = (str32.len - pos32), .text = str32.text + pos32 };
-        struct utf32_decode_result decoded = utf32_decode(str32_remaining);
-        struct utf8_encode_result encoded = utf8_encode(decoded.codepoint);
-
-        u8 *dest = arena_push_array(arena, u8, encoded.count8);
-        MEMCPY(dest, &encoded.chars8, encoded.count8);
-
-        pos32 += 1;
-        res.len += encoded.count8;
-    }
-
-    return res;
-}
-
 /* utf32 <- utf8 */
 struct string32 string32_from_string(struct arena *arena, struct string str8)
 {
@@ -647,3 +562,93 @@ struct string32 string32_from_string(struct arena *arena, struct string str8)
 
     return res;
 }
+
+/* ========================== *
+ * Legacy strings
+ * ========================== */
+
+/* C narrow strings */
+
+u64 cstr_len(char *cstr)
+{
+    char *end = cstr;
+    while (*end) {
+        ++end;
+    }
+    return end - cstr;
+}
+
+char *cstr_from_string(struct arena *arena, struct string src)
+{
+    u8 *text = arena_push_array(arena, u8, src.len + 1);
+    MEMCPY(text, src.text, src.len);
+    text[src.len] = 0;
+    return (char *)text;
+}
+
+char *cstr_buff_from_string(struct buffer dest_buff, struct string src)
+{
+    if (dest_buff.size > 0) {
+        u64 len = min_u64(src.len, dest_buff.size - 1);
+        MEMCPY(dest_buff.data, src.text, len);
+        dest_buff.data[len] = 0;
+    }
+    return (char *)dest_buff.data;
+}
+
+struct string string_from_cstr(char *cstr)
+{
+    u64 len = cstr_len(cstr);
+    return (struct string) {
+        .len = len,
+        .text = (u8 *)cstr
+    };
+}
+
+struct string string_from_cstr_len(char *cstr, u64 len)
+{
+    return (struct string) {
+        .text = (u8 *)cstr,
+        .len = len
+    };
+}
+
+/* C wide strings */
+
+u64 wstr_len(wchar_t *wstr)
+{
+    wchar_t *end = wstr;
+    while (*end) {
+        ++end;
+    }
+    return end - wstr;
+}
+
+wchar_t *wstr_from_string(struct arena *arena, struct string src)
+{
+    struct string16 str16 = string16_from_string(arena, src);
+    *arena_push(arena, u16) = 0;
+    return (wchar_t *)str16.text;
+}
+
+wchar_t *wstr_from_string16(struct arena *arena, struct string16 src)
+{
+    u16 *text = arena_push_array(arena, u16, src.len + 1);
+    text[src.len] = 0;
+    return (wchar_t *)text;
+}
+
+struct string string_from_wstr(struct arena *arena, wchar_t *wstr)
+{
+    struct string16 str16 = string16_from_wstr(wstr);
+    return string_from_string16(arena, str16);
+}
+
+struct string16 string16_from_wstr(wchar_t *wstr)
+{
+    u64 len = wstr_len(wstr);
+    return (struct string16) {
+        .len = len,
+        .text = (u16 *)wstr
+    };
+}
diff --git a/src/string.h b/src/string.h
index c5f3d10e..f31b25b3 100644
--- a/src/string.h
+++ b/src/string.h
@@ -21,9 +21,7 @@ struct string string_from_float(struct arena *arena, f64 f, u32 precision);
  * ========================== */
 
 struct string string_copy(struct arena *arena, struct string src);
-struct string string_copy_buff(struct buffer buff, struct string src);
-struct string string_from_cstr(char *cstr);
-struct string string_from_cstr_len(char *cstr, u64 len);
+struct string string_copy_buff(struct buffer dest_buff, struct string src);
 struct string string_repeat(struct arena *arena, struct string src, u64 count);
 struct string string_cat(struct arena *arena, struct string str1, struct string str2);
 struct string_array string_split(struct arena *arena, struct string str, struct string delim);
@@ -32,9 +30,6 @@ b32 string_eq(struct string str1, struct string str2);
 b32 string_contains(struct string str, struct string substring);
 b32 string_starts_with(struct string str, struct string substring);
 b32 string_ends_with(struct string str, struct string substring);
-char *string_to_cstr(struct arena *arena, struct string str);
-char *string_to_cstr_buff(struct string str, struct buffer buff);
-wchar_t *string_to_wstr(struct arena *arena, struct string str);
 
 /* ========================== *
  * Format
@@ -86,12 +81,28 @@ struct string _string_format(struct arena *arena, struct string fmt, ...);
 struct string string_formatv(struct arena *arena, struct string fmt, va_list args);
 
 /* ========================== *
- * Unicode transformation
+ * Unicode
  * ========================== */
 
 struct string string_from_string16(struct arena *arena, struct string16 str16);
-struct string16 string16_from_string(struct arena *arena, struct string str8);
 struct string string_from_string32(struct arena *arena, struct string32 str32);
+struct string16 string16_from_string(struct arena *arena, struct string str8);
 struct string32 string32_from_string(struct arena *arena, struct string str8);
 
+/* ========================== *
+ * Legacy strings
+ * ========================== */
+
+u64 cstr_len(char *cstr);
+char *cstr_from_string(struct arena *arena, struct string src);
+char *cstr_buff_from_string(struct buffer dest_buff, struct string src);
+struct string string_from_cstr(char *cstr);
+struct string string_from_cstr_len(char *cstr, u64 len);
+
+u64 wstr_len(wchar_t *wstr);
+wchar_t *wstr_from_string(struct arena *arena, struct string src);
+wchar_t *wstr_from_string16(struct arena *arena, struct string16 src);
+struct string string_from_wstr(struct arena *arena, wchar_t *wstr);
+struct string16 string16_from_wstr(wchar_t *wstr);
+
 #endif
diff --git a/src/sys.h b/src/sys.h
index bf42aa10..c8c5b56c 100644
--- a/src/sys.h
+++ b/src/sys.h
@@ -195,8 +195,8 @@ u64 sys_file_size(struct sys_file file);
  * ========================== */
 
 struct sys_file_map {
-    u64 handle;
     struct buffer mapped_memory;
+    u64 handle;
 };
 
 struct sys_file_map sys_file_map_open_read(struct sys_file file);
@@ -207,18 +207,20 @@ struct buffer sys_file_map_data(struct sys_file_map map);
  * Dir iter
  * ========================== */
 
-/* Opaque */
-struct sys_dir_iter;
-
-struct sys_dir_iter_info {
-    struct string file_name;
+struct sys_file_filter_result {
+    struct string filename;
     b32 is_dir;
 };
 
+struct sys_file_filter {
+    struct sys_file_filter_result info;
+    u64 handle;
+};
+
 /* Iterate all files in a directory */
-struct sys_dir_iter *sys_dir_iter_begin(struct arena *arena, struct string dir_name);
-struct sys_dir_iter_info *sys_dir_iter_next(struct arena *arena, struct sys_dir_iter *iter);
-void sys_dir_iter_end(struct sys_dir_iter *iter);
+struct sys_file_filter sys_file_filter_begin(struct arena *arena, struct string pattern);
+b32 sys_file_filter_next(struct arena *arena, struct sys_file_filter *iter);
+void sys_file_filter_end(struct sys_file_filter *iter);
 
 /* ========================== *
  * Window
diff --git a/src/sys_win32.c b/src/sys_win32.c
index 3bb82a86..8ac11c14 100644
--- a/src/sys_win32.c
+++ b/src/sys_win32.c
@@ -10,6 +10,7 @@
 #include "math.h"
 #include "util.h"
 #include "tls.h"
+#include "utf.h"
 
 #include <Windows.h>
 #include <windowsx.h>
@@ -27,6 +28,7 @@
 #pragma comment(lib, "dwmapi")
 
 #define SYS_WINDOW_EVENT_LISTENERS_MAX 512
+#define WINDOW_CLASS_NAME L"power_play_window_class"
 
 struct win32_thread_params {
     sys_thread_func *thread_func;
@@ -107,7 +109,7 @@ GLOBAL struct {
     struct win32_thread_params *first_free_thread_params;
 
     /* Windows */
-    WNDCLASSEX window_class;
+    WNDCLASSEXW window_class;
     struct sys_mutex windows_mutex;
     struct arena windows_arena;
     struct win32_window *first_free_window;
@@ -187,39 +189,39 @@ void sys_memory_decommit(void *address, u64 size)
     VirtualFree(address, size, MEM_DECOMMIT);
 }
 
-/* ========================== *
- * Wchar
- *
- * TODO: Move wide char ops to string.c and actually do proper decoding
- * ========================== */
-
-INTERNAL struct string wchar_path_to_string(struct arena *arena, wchar_t *src)
-{
-    struct string str = { 0, arena_dry_push(arena, u8) };
-    while (1) {
-        wchar_t wchar = src[str.len];
-        if (wchar != 0) {
-            if (wchar == '\\') {
-                wchar = '/';
-            }
-            u8 *c = arena_push(arena, u8);
-            /* FIXME: We're ignoring the high byte here */
-            *c = (u8)(wchar & 0xFF);
-            ++str.len;
-        } else {
-            break;
-        }
-    }
-    return str;
-}
-
 /* ========================== *
  * File system
  * ========================== */
 
+INTERNAL struct string string_from_win32_path(struct arena *arena, wchar_t *src)
+{
+    struct string res = {
+        .len = 0,
+        .text = arena_dry_push(arena, u8)
+    };
+
+    while (*src) {
+        struct string16 decode_str = { .len = *(src + 1) ? 2 : 1, .text = src };
+        struct utf16_decode_result decoded = utf16_decode(decode_str);
+        struct utf8_encode_result encoded = utf8_encode(decoded.codepoint);
+        u8 *dest = arena_push_array(arena, u8, encoded.count8);
+        for (u32 i = 0; i < encoded.count8; ++i) {
+            u8 byte = encoded.chars8[i];
+            if (byte == '\\') {
+                byte = '/';
+            }
+            dest[i] = byte;
+        }
+        res.len += encoded.count8;
+        src += decoded.advance16;
+    }
+
+    return res;
+}
+
 struct string sys_get_write_path(struct arena *arena)
 {
-    wchar_t *p = NULL;
+    u16 *p = NULL;
     /* TODO: cache this? */
     HRESULT res = SHGetKnownFolderPath(
         &FOLDERID_LocalAppData,
@@ -229,7 +231,7 @@ struct string sys_get_write_path(struct arena *arena)
     );
     struct string path = { 0 };
     if (res == S_OK) {
-        path = wchar_path_to_string(arena, p);
+        path = string_from_win32_path(arena, p);
     }
     CoTaskMemFree(p);
     return path;
@@ -239,8 +241,8 @@ b32 sys_is_file(struct string path)
 {
     __prof;
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
-    DWORD attributes = GetFileAttributes(path_cstr);
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
+    DWORD attributes = GetFileAttributesW(path_wstr);
     scratch_end(scratch);
     return attributes != INVALID_FILE_ATTRIBUTES && !(attributes & FILE_ATTRIBUTE_DIRECTORY);
 }
@@ -248,8 +250,8 @@ b32 sys_is_file(struct string path)
 b32 sys_is_dir(struct string path)
 {
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
-    DWORD attributes = GetFileAttributes(path_cstr);
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
+    DWORD attributes = GetFileAttributesW(path_wstr);
     scratch_end(scratch);
     return attributes != INVALID_FILE_ATTRIBUTES && (attributes & FILE_ATTRIBUTE_DIRECTORY);
 }
@@ -258,10 +260,35 @@ void sys_mkdir(struct string path)
 {
     __prof;
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
-    b32 success = SHCreateDirectoryExA(NULL, path_cstr, NULL) == ERROR_SUCCESS;
-    (UNUSED)success;
-    ASSERT(success);
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
+    int err_code = SHCreateDirectory(NULL, path_wstr);
+    struct string err = { 0 };
+    switch (err_code) {
+        case ERROR_BAD_PATHNAME: {
+            err = STR("Bad path name");
+        } break;
+
+        case ERROR_FILENAME_EXCED_RANGE: {
+            err = STR("Path name too long");
+        } break;
+
+        case ERROR_FILE_EXISTS: {
+            err = STR("A file already exists at this location");
+        } break;
+
+        case ERROR_CANCELLED: {
+            err = STR("User canceled the operation");
+        } break;
+
+        default: break;
+    }
+    if (err.len > 0) {
+        struct string msg = string_format(scratch.arena,
+                                          STR("Failed to create directory \"%F\": %F"),
+                                          FMT_STR(path),
+                                          FMT_STR(err));
+        sys_panic(msg);
+    }
     scratch_end(scratch);
 }
 
@@ -269,11 +296,11 @@ struct sys_file sys_file_open_read(struct string path)
 {
     __prof;
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
 
     /* TODO: Handle errors / non-existing file (handle == INVALID_HANDLE_VALUE) */
-    HANDLE handle = CreateFileA(
-        path_cstr,
+    HANDLE handle = CreateFileW(
+        path_wstr,
         GENERIC_READ,
         FILE_SHARE_READ,
         NULL,
@@ -290,9 +317,9 @@ struct sys_file sys_file_open_write(struct string path)
 {
     __prof;
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
-    HANDLE handle = CreateFileA(
-        path_cstr,
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
+    HANDLE handle = CreateFileW(
+        path_wstr,
         GENERIC_WRITE,
         0,
         NULL,
@@ -310,9 +337,9 @@ struct sys_file sys_file_open_append(struct string path)
 {
     __prof;
     struct temp_arena scratch = scratch_begin_no_conflict();
-    const char *path_cstr = string_to_cstr(scratch.arena, path);
-    HANDLE handle = CreateFileA(
-        path_cstr,
+    wchar_t *path_wstr = wstr_from_string(scratch.arena, path);
+    HANDLE handle = CreateFileW(
+        path_wstr,
         FILE_APPEND_DATA,
         FILE_SHARE_READ,
         NULL,
@@ -395,7 +422,7 @@ u64 sys_file_size(struct sys_file file)
 
 struct sys_file_map sys_file_map_open_read(struct sys_file file)
 {
-    HANDLE map_handle = CreateFileMappingA(
+    HANDLE map_handle = CreateFileMappingW(
         (HANDLE)file.handle,
         NULL,
         PAGE_READONLY,
@@ -451,60 +478,57 @@ struct buffer sys_file_map_data(struct sys_file_map map)
 }
 
 /* ========================== *
- * Dir iter
+ * File iter
  * ========================== */
 
-struct sys_dir_iter {
-    HANDLE handle;
-    char *dir_path_cstr;
+struct win32_file_filter {
+    HANDLE find_handle;
+    wchar_t *filter_wstr;
 };
 
-struct sys_dir_iter *sys_dir_iter_begin(struct arena *arena, struct string dir_name)
+struct sys_file_filter sys_file_filter_begin(struct arena *arena, struct string pattern)
 {
-    struct temp_arena scratch = scratch_begin(arena);
-    struct sys_dir_iter *iter = arena_push_zero(arena, struct sys_dir_iter);
-    if (dir_name.len >= 1 && dir_name.text[dir_name.len - 1] == '/') {
-        struct string dir_path_w_asterisk = string_cat(scratch.arena, dir_name, STR("*"));
-        iter->dir_path_cstr = string_to_cstr(arena, dir_path_w_asterisk);
-    } else {
-        /* Invalid directory path supplied */
-        ASSERT(false);
-    }
-    scratch_end(scratch);
-    return iter;
+    struct sys_file_filter filter = { 0 };
+    struct win32_file_filter *filter_internal = arena_push_zero(arena, struct win32_file_filter);
+    filter_internal->filter_wstr = wstr_from_string(arena, pattern);
+    filter.handle = (u64)filter_internal;
+    return filter;
 }
 
-struct sys_dir_iter_info *sys_dir_iter_next(struct arena *arena, struct sys_dir_iter *iter)
+b32 sys_file_filter_next(struct arena *arena, struct sys_file_filter *filter)
 {
-    WIN32_FIND_DATA find_file_data = { 0 };
+    struct win32_file_filter *filter_internal = (struct win32_file_filter *)filter->handle;
+
+    WIN32_FIND_DATAW find_file_data = { 0 };
     b32 found = false;
 
-    if (iter->handle) {
-        found = FindNextFileA(iter->handle, &find_file_data);
-    } else if (iter->dir_path_cstr) {
-        iter->handle = FindFirstFileExA(iter->dir_path_cstr, FindExInfoStandard, &find_file_data, FindExSearchNameMatch, NULL, FIND_FIRST_EX_LARGE_FETCH);
-        found = iter->handle != INVALID_HANDLE_VALUE;
+    if (filter_internal->find_handle) {
+        found = FindNextFileW(filter_internal->find_handle, &find_file_data);
+    } else {
+        filter_internal->find_handle = FindFirstFileExW(filter_internal->filter_wstr, FindExInfoStandard, &find_file_data, FindExSearchNameMatch, NULL, FIND_FIRST_EX_CASE_SENSITIVE | FIND_FIRST_EX_LARGE_FETCH);
+        found = filter_internal->find_handle != INVALID_HANDLE_VALUE;
     }
 
-    struct sys_dir_iter_info *info = NULL;
     if (found) {
-        struct string file_name = string_from_cstr(find_file_data.cFileName);
+        struct string file_name = string_from_wstr(arena, find_file_data.cFileName);
         if (string_eq(file_name, STR(".")) || string_eq(file_name, STR(".."))) {
             /* Skip initial '.' and '..' matches */
-            info = sys_dir_iter_next(arena, iter);
+            found = sys_file_filter_next(arena, filter);
         } else {
-            info = arena_push_zero(arena, struct sys_dir_iter_info);
-            info->is_dir = find_file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
-            info->file_name = string_copy(arena, file_name);
+            filter->info.is_dir = find_file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
+            filter->info.filename = string_copy(arena, file_name);
         }
     }
 
-    return info;
+    return found;
 }
 
-void sys_dir_iter_end(struct sys_dir_iter *iter)
+void sys_file_filter_end(struct sys_file_filter *filter)
 {
-    FindClose(iter->handle);
+    struct win32_file_filter *filter_internal = (struct win32_file_filter *)filter->handle;
+    if (filter_internal->find_handle) {
+        FindClose(filter_internal->find_handle);
+    }
 }
 
 /* ========================== *
@@ -536,10 +560,10 @@ INTERNAL HWND win32_create_window(struct win32_window *window)
     DWORD exstyle = WS_EX_APPWINDOW | WS_EX_NOREDIRECTIONBITMAP;
 
     /* TODO: Check for hwnd success */
-    HWND hwnd = CreateWindowExA(
+    HWND hwnd = CreateWindowExW(
         exstyle,
         L.window_class.lpszClassName,
-        "",
+        L"",
         WS_OVERLAPPEDWINDOW,
         CW_USEDEFAULT,
         CW_USEDEFAULT,
@@ -556,7 +580,7 @@ INTERNAL HWND win32_create_window(struct win32_window *window)
     DwmSetWindowAttribute(hwnd, DWMWA_USE_IMMERSIVE_DARK_MODE, (LPCVOID)&dark_mode, sizeof(dark_mode));
 
     /* Set window as userdata */
-    SetWindowLongPtrA(hwnd, GWLP_USERDATA, (LONG_PTR)window);
+    SetWindowLongPtrW(hwnd, GWLP_USERDATA, (LONG_PTR)window);
 
     return hwnd;
 }
@@ -779,7 +803,7 @@ INTERNAL void win32_update_window_from_settings(struct win32_window *window, str
     if (fullscreen) {
         if (!old_fullscreen) {
             /* Entering fullscreen */
-            SetWindowLongPtrA(hwnd, GWL_STYLE, WS_POPUP);
+            SetWindowLongPtrW(hwnd, GWL_STYLE, WS_POPUP);
         }
         rect = (RECT) {
             .left = 0,
@@ -790,7 +814,7 @@ INTERNAL void win32_update_window_from_settings(struct win32_window *window, str
     } else {
         if (old_fullscreen) {
             /* Leaving fullscreen */
-            SetWindowLongPtrA(hwnd, GWL_STYLE, WS_OVERLAPPEDWINDOW);
+            SetWindowLongPtrW(hwnd, GWL_STYLE, WS_OVERLAPPEDWINDOW);
         }
         rect = (RECT) {
             .left = settings->floating_x,
@@ -808,21 +832,26 @@ INTERNAL void win32_update_window_from_settings(struct win32_window *window, str
     };
     SetWindowPlacement(hwnd, &wp);
 
-    SetWindowTextA(hwnd, settings->title);
+    {
+        struct temp_arena scratch = scratch_begin_no_conflict();
+        wchar_t *title_wstr = wstr_from_string(scratch.arena, string_from_cstr(settings->title));
+        SetWindowTextW(hwnd, title_wstr);
+        scratch_end(scratch);
+    }
 }
 
 INTERNAL void win32_window_wake(struct win32_window *window)
 {
     /* Post a blank message to the window's thread message queue to wake it. */
-    PostMessageA(window->hwnd, WM_NULL, 0, 0);
+    PostMessageW(window->hwnd, WM_NULL, 0, 0);
 }
 
 INTERNAL LRESULT CALLBACK win32_window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
 {
-    struct win32_window *window = (struct win32_window *)GetWindowLongPtrA(hwnd, GWLP_USERDATA);
+    struct win32_window *window = (struct win32_window *)GetWindowLongPtrW(hwnd, GWLP_USERDATA);
 
     if (!window) {
-        return DefWindowProcA(hwnd, msg, wparam, lparam);
+        return DefWindowProcW(hwnd, msg, wparam, lparam);
     }
 
     LRESULT result = 0;
@@ -834,7 +863,7 @@ INTERNAL LRESULT CALLBACK win32_window_proc(HWND hwnd, UINT msg, WPARAM wparam,
         } break;
 
         case WM_PAINT: {
-            result = DefWindowProcA(hwnd, msg, wparam, lparam);
+            result = DefWindowProcW(hwnd, msg, wparam, lparam);
         } break;
 
         case WM_MOVE:
@@ -842,13 +871,13 @@ INTERNAL LRESULT CALLBACK win32_window_proc(HWND hwnd, UINT msg, WPARAM wparam,
         case WM_SIZE:
         case WM_SIZING: {
             win32_update_window_from_system(window);
-            result = DefWindowProcA(hwnd, msg, wparam, lparam);
+            result = DefWindowProcW(hwnd, msg, wparam, lparam);
         } break;
 
         /* Keyboard buttons */
         case WM_SYSKEYUP:
         case WM_SYSKEYDOWN: {
-            result = DefWindowProcA(hwnd, msg, wparam, lparam);
+            result = DefWindowProcW(hwnd, msg, wparam, lparam);
         } FALLTHROUGH;
         case WM_KEYUP:
         case WM_KEYDOWN: {
@@ -997,7 +1026,7 @@ INTERNAL LRESULT CALLBACK win32_window_proc(HWND hwnd, UINT msg, WPARAM wparam,
 
 
         default: {
-            result = DefWindowProcA(hwnd, msg, wparam, lparam);
+            result = DefWindowProcW(hwnd, msg, wparam, lparam);
         } break;
     }
 
@@ -1476,7 +1505,7 @@ INTERNAL DWORD WINAPI win32_thread_proc(LPVOID params)
     struct string thread_name = string_from_cstr(thread_params.thread_name_cstr);
     if (thread_name.len > 0) {
         struct temp_arena scratch = scratch_begin_no_conflict();
-        wchar_t *wc_thread_name = string_to_wstr(scratch.arena, thread_name);
+        wchar_t *wc_thread_name = wstr_from_string(scratch.arena, thread_name);
         SetThreadDescription(GetCurrentThread(), wc_thread_name);
         scratch_end(scratch);
     }
@@ -1509,7 +1538,7 @@ struct sys_thread sys_thread_init(sys_thread_func *thread_func, void *thread_dat
     tp->thread_data = thread_data;
 
     /* Copy thread name to params */
-    string_to_cstr_buff(thread_name, BUFFER_FROM_ARRAY(tp->thread_name_cstr));
+    cstr_buff_from_string(BUFFER_FROM_ARRAY(tp->thread_name_cstr), thread_name);
 
     HANDLE handle = CreateThread(
         NULL,
@@ -1558,10 +1587,10 @@ void sys_thread_assert(u32 tid)
 
 void sys_message_box(enum sys_message_box_kind kind, struct string message)
 {
-    char message_buff[4096] = { 0 };
-    char *message_cstr = string_to_cstr_buff(message, BUFFER_FROM_ARRAY(message_buff));
+    struct temp_arena scratch = scratch_begin_no_conflict();
+    wchar_t *message_wstr = wstr_from_string(scratch.arena, message);
 
-    const char *title = "";
+    const wchar_t *title = L"";
     UINT mbox_type = 0;
 
     switch (kind) {
@@ -1570,22 +1599,24 @@ void sys_message_box(enum sys_message_box_kind kind, struct string message)
         } break;
 
         case SYS_MESSAGE_BOX_KIND_WARNING: {
-            title = "Warning";
+            title = L"Warning";
             mbox_type = MB_ICONWARNING;
         } break;
 
         case SYS_MESSAGE_BOX_KIND_ERROR: {
-            title = "Error";
+            title = L"Error";
             mbox_type = MB_ICONERROR;
         } break;
 
         case SYS_MESSAGE_BOX_KIND_FATAL: {
-            title = "Fatal error";
+            title = L"Fatal error";
             mbox_type = MB_ICONSTOP;
         } break;
     }
 
-    MessageBoxExA(NULL, message_cstr, title, mbox_type, 0);
+    MessageBoxExW(NULL, message_wstr, title, mbox_type, 0);
+
+    scratch_end(scratch);
 }
 
 /* ========================== *
@@ -1650,21 +1681,30 @@ u32 sys_rand_u32(void)
     return v;
 }
 
-void sys_panic_raw(char *msg_cstr)
+INTERNAL void panic_exit(void)
 {
-    /* FIXME: Exit other threads before showing message box */
-    MessageBoxExA(NULL, msg_cstr, "Fatal error", MB_ICONSTOP, 0);
     ASSERT(false);
     sys_exit();
 }
 
+void sys_panic_raw(char *msg_cstr)
+{
+    /* FIXME: Exit other threads before showing message box */
+    MessageBoxExA(NULL, msg_cstr, "Fatal error", MB_ICONSTOP, 0);
+    panic_exit();
+}
+
 void sys_panic(struct string msg)
 {
-    struct temp_arena scratch = scratch_begin_no_conflict();
+    /* FIXME: Exit other threads before showing message box */
     logf_critical("Panicking: %F", FMT_STR(msg));
-    struct string prepend = STR("A fatal error has occured and the application needs to exit:\n\n");
-    msg = string_cat(scratch.arena, prepend, msg);
-    sys_panic_raw(string_to_cstr(scratch.arena, msg));
+    struct temp_arena scratch = scratch_begin_no_conflict();
+    msg = string_cat(scratch.arena,
+                     STR("A fatal error has occured and the application needs to exit:\n\n"),
+                     msg);
+    wchar_t *msg_wstr = wstr_from_string(scratch.arena, msg);
+    MessageBoxExW(NULL, msg_wstr, L"Fatal error", MB_ICONSTOP, 0);
+    panic_exit();
     scratch_end(scratch);
 }
 
@@ -1782,14 +1822,14 @@ INTERNAL SYS_THREAD_FUNC_DEF(app_thread_entry_point, arg)
     app_entry_point();
 }
 
-int CALLBACK WinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance, _In_ LPSTR command_line, _In_ int show_code)
+int CALLBACK wWinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance, _In_ LPWSTR command_line, _In_ int show_code)
 {
     (UNUSED)instance;
     (UNUSED)prev_instance;
     (UNUSED)command_line;
     (UNUSED)show_code;
 
-    const char *error_msg = NULL;
+    const wchar_t *error_msg = NULL;
 
     SetThreadDescription(GetCurrentThread(), L"Main thread");
 
@@ -1816,7 +1856,7 @@ int CALLBACK WinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance,
     L.thread_tls_index = TlsAlloc();
     if (L.thread_tls_index == TLS_OUT_OF_INDEXES) {
         /* TODO: GetLastError */
-        error_msg = "Platform initialization error: TLS_OUT_OF_INDEXES";
+        error_msg = L"Platform initialization error: TLS_OUT_OF_INDEXES";
         goto error;
     }
 
@@ -1840,9 +1880,9 @@ int CALLBACK WinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance,
     /* Create window class */
     {
         /* Register the window class */
-        WNDCLASSEX *wc = &L.window_class;
+        WNDCLASSEXW *wc = &L.window_class;
         wc->cbSize = sizeof(WNDCLASSEX);
-        wc->lpszClassName = "power_play_window_class";
+        wc->lpszClassName = WINDOW_CLASS_NAME;
         wc->hCursor = LoadCursor(NULL, IDC_ARROW);
         wc->style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
         //wc->hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
@@ -1854,9 +1894,9 @@ int CALLBACK WinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance,
         GetModuleFileName(instance, path, MAX_PATH);
         ExtractIconEx(path, 0, &wc->hIcon, &wc->hIconSm, 1);
 
-        if (!RegisterClassExA(wc)) {
+        if (!RegisterClassExW(wc)) {
             /* TODO: GetLastError */
-            error_msg = "Failed to register window class";
+            error_msg = L"Failed to register window class";
             goto error;
         }
     }
@@ -1871,14 +1911,14 @@ int CALLBACK WinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev_instance,
 
         if (!RegisterRawInputDevices(&rid, 1, sizeof(rid))) {
             /* TODO: GetLastError */
-            error_msg = "Failed to register raw input device";
+            error_msg = L"Failed to register raw input device";
             goto error;
         }
     }
 
 error:
     if (error_msg) {
-        MessageBoxExA(NULL, error_msg, "Fatal initialization error", MB_ICONSTOP, 0);
+        MessageBoxExW(NULL, error_msg, L"Fatal initialization error", MB_ICONSTOP, 0);
         ASSERT(false);
         return 1;
     }
@@ -1910,9 +1950,9 @@ __attribute((used))
 int _fltused;
 
 __attribute((used))
-void __stdcall WinMainCRTStartup(void)
+void __stdcall wWinMainCRTStartup(void)
 {
-    int result = WinMain(GetModuleHandle(0), 0, GetCommandLineA(), 0);
+    int result = wWinMain(GetModuleHandle(0), 0, GetCommandLineW(), 0);
     ExitProcess(result);
 }
 
diff --git a/src/texture.c b/src/texture.c
index 3d004504..ba96da21 100644
--- a/src/texture.c
+++ b/src/texture.c
@@ -247,7 +247,7 @@ struct asset *texture_load_asset(struct string path, b32 help)
                                     STR("Texture path \"%F\" too long!"),
                                     FMT_STR(path)));
         }
-        string_to_cstr_buff(path, BUFFER_FROM_ARRAY(params->path_cstr));
+        cstr_buff_from_string(BUFFER_FROM_ARRAY(params->path_cstr), path);
         params->path_len = path.len;
         params->asset = asset;