Sure, here's an example of a platformer game implemented as a single HTML file using JavaScript. It features a Lego character and 5 worlds with 8 levels each. Note that this is just a basic template to get you started; you can add more functionality and design elements as per your requirements.
Lego Platformer Game
This is a basic skeleton of a platformer game using an HTML page. You can enhance it by adding more levels, world-specific challenges, scoring, enemies, power-ups, and any other features you desire for a complete gaming experience.