Sure, here's an example of a simple evolution simulation game implemented as a single HTML file using JavaScript:
In this game, organisms are represented as blue squares (you can change the styling to use pictograms instead) and they grow over time. The organisms can reproduce when their energy reaches 100. They die if their age exceeds 10 or their energy drops below 0.
The simulation keeps running and updates the game visually by adding/removing organisms and displaying their age. Feel free to modify the code and add more features to make it a more complex and interactive evolution simulation game.