Sure! Here's an example of a game about jumping over spikes and running from cops using JavaScript within a single HTML file:
In this game, the player controls a blue square which can jump by pressing the spacebar. The objective is to avoid the red spike and the yellow cop by jumping over them. The game ends if the player collides with the spike or the cop. The game is designed to be playable on a smartphone using touch controls.
Note: This is a simple implementation to demonstrate the basic game mechanics. You can enhance it further with additional levels, score tracking, sound effects, etc., according to your requirements.