Sure, here's an example of a simple game called "Kill House" implemented as a single HTML file using JavaScript:
Kill House - Find the Imposter
This game presents the player with four color options displayed as filled rectangles. One of these colors is randomly selected as the "imposter." The player's objective is to identify the correct imposter color by clicking on it. If the player clicks on the correct imposter color, a congratulatory message will be displayed. Otherwise, they will receive a message to try again.
Please note that this is a very basic game implementation and can be expanded upon with additional features, animations, and gameplay elements.