Sure! Here's an example of a simple game called "Air Oxygen" implemented as a single HTML file, containing JavaScript code enclosed in script tags. This game simulates collecting oxygen for a character in order to survive. Let's assume it can be played on a smartphone.
Air Oxygen Game
This game uses a canvas element to draw the character and oxygen level. The player controls the character's movement by dragging on the screen. The goal is to keep collecting oxygen (displayed as a red bar) to stay alive. If the oxygen level reaches 0, the game over condition is triggered. The code also handles touch events for smartphone operation.
Note: This is a simplified example to demonstrate the game structure. You can enhance the game with additional features, graphics, levels, and refine the gameplay as per your requirements.