What it is
You work for the Meridian Combine, taking claims in frontier country. There is combat with issued weapons, an inventory, contracts to accept, and time dilation you can lean on when a fight turns. The interface is text and structured data blocks rather than illustration, and the tone is corporate science fiction: “It is not the best venture. It is the only venture.”
The constraint is the headline
The whole game is one HTML file, 675 KB. No build step, no bundler, no dependencies, no server. Open the file and it runs.
That is the interesting part. Most things that behave like this arrive as a project directory and a package manifest. This arrives as a file you could email.
Controls
WASD to move, mouse to aim and fire, shift for time dilation, tab for inventory, Q for a medkit. Desktop only, and honestly so: it needs a keyboard and a mouse, so it says that rather than degrading into something unplayable on a phone.