Sure! Here's an example of a game implemented as a single HTML file, using JavaScript and enclosed in script tags:
This HTML file creates a game where you can control the movement of an emoji using arrow buttons. The emoji starts in the middle of the screen, and you can move it left, right, up, and down.
Additionally, you can transform the emoji into a dragon by tapping the space bar. Tapping it again will transform it back into an emoji. The dragon and emoji are represented by pictograms.
Please note that this is a simple example and may require further modifications or enhancements to fit your specific game requirements.