Sure, here's an example of a simple Mario game implemented as a single HTML file using JavaScript. Please note that this is a simplified version and does not include extensive gameplay or levels.
This example sets up a simple Mario game that can be played on a smartphone. The game area is defined by the `game` div, and Mario's character is represented by the `mario` div. When the player taps the game area, Mario jumps up due to an applied velocity. Gravity is constantly applied to Mario, causing him to fall back down. The game loop keeps updating Mario's position and checks for collisions if required.
Please note that this is just a basic example and would need additional development to become a fully playable game with levels, enemies, and more features.