Sure! Here's a simple implementation of the classic game Pac-Man in a single HTML file using JavaScript:
This implementation creates a Pac-Man character represented by a yellow circle. You can control Pac-Man's movement using the arrow keys on your smartphone. The game canvas is responsive and will resize to fit the screen.
Note that this is a simple implementation and lacks elements such as ghosts, pellets, and scoring. You can further expand on the code to add these features and complete the game according to your requirements.