Sure! Here's an example of a simple platformer game using JavaScript and HTML:
This is a basic platformer game where you control a red player and try to navigate through green platforms. Simply tap/click anywhere on the game area to make the player jump. The player is affected by gravity and collides with the platforms.
Please note that this is a simplified example and does not include all the features and complexity of a game like Mario. However, it should give you a starting point to build upon and add more functionality.