Add a new platformer game with various levels and enemies

The agent has updated the game's core logic, including player movement, enemy AI, collision detection, and level loading. New sprites and sound effects have been integrated, along with the addition of a Chess game. The replit.nix file has been configured to include jdk21 and neovim.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: f6819c21-e85d-45ac-acde-604db2cfa4fe
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 32bc3e83-133e-4485-96b6-ff3d548bcbfd
Replit-Helium-Checkpoint-Created: true

American-Identity-Project/Collectable.java

@@ -0,0 +1,7 @@
+import javax.swing.ImageIcon;
+
+public class Collectable extends Collidable {
+  public Collectable(int x, int y, int w, int h, ImageIcon i) {
+    super(x, y, w, h, i);
+  }
+}