Add tile graphic

src/main.rs

@@ -2,11 +2,22 @@ mod app;
 mod game;
 mod graphics;
 mod math;
+mod res;
 mod world;
 
 use app::App;
 
-fn main() {
-    let mut app = App::new();
+fn try_main() -> anyhow::Result<()> {
+    let mut app = App::new()?;
     app.do_game_loop();
+    Ok(())
+}
+
+fn main() {
+    if let Err(e) = try_main() {
+        rfd::MessageDialog::new()
+            .set_title("Fatal error")
+            .set_description(&e.to_string())
+            .show();
+    }
 }