Sure, here's a simple 2D pixel game similar to Pokémon implemented as a single HTML file:
This game sets up a canvas element and a player character object (`player`) that can be moved around using the arrow keys. The player character is represented by a blue rectangle, and its position is updated based on user input. The canvas is cleared and the player character is redrawn in each frame of the game loop. You can further enhance the game by adding more features, such as enemies, items, and battles, according to your desired Pokémon-inspired gameplay.