Sure! Here's a simple platformer game about the movie "Cats and Dogs" implemented as a single HTML file using JavaScript:
Cats and Dogs Platformer Game
In this game, you control a character represented by a red square using the arrow keys on your smartphone. The goal is to move the character on the gray platforms without falling off. The player will stop falling when colliding with a platform. The game updates every 20 milliseconds to check for collisions and player movement.