Sure! Here's an example of a simple game written in a single HTML file using JavaScript, featuring finding keys to unlock a door and a zombie shooter.
Zombie Escape
🤺
In this game, the player's objective is to find three keys to unlock the door by clicking on it. Once all three keys are found, the door will change color to indicate it is unlocked. Additionally, there are three zombies represented by pictograms that can be "shot" by clicking the player pictogram. The number of zombies remaining is displayed below the player.