Create a Marvel-themed version of the 2048 game. Instead of numbers, use Marvel characters that "merge" into stronger characters. For example, start with Hawkeye and Black Widow, which combine into Captain America, then Iron Man, then Thor, then Hulk, then Doctor Strange, and so on. Each merge should upgrade to a more powerful or iconic Marvel hero or villain, ending with Thanos as the final tile. Replace the number tiles with character images or names. Use vibrant colors, add subtle superhero-themed animations when tiles merge (like a flash, explosion, or spark), and play a short sound effect when a merge happens. Keep the classic swipe gameplay but use a modern Marvel-style font and UI. Make sure the game ends when the board is full and no merges are possible, and display a "You defeated Thanos!" message if the player reaches the final tile.