Sure, here's an example of a simple stealth game implemented as a single HTML file using JavaScript:
In this game, you control a red square (representing the virus) using touch or mouse input to move around the screen and try to "possess" green squares (representing cyborgs) by colliding with them. When you possess a cyborg, your red square changes color to match the cyborg, allowing you to hide from other cyborgs. However, you cannot hide from the yellow square (representing people trying to delete you, i.e., antivirus programs). If you collide with the yellow square, the game ends.
The score is displayed at the top right corner of the screen, showing the number of successfully possessed cyborgs.