A first-person shooter written in Turbo Pascal, with an integer-maths 3D engine, because floating point was not on the menu in 1995 and it turns out it still is not needed. This is the real DOS binary, running on a WebAssembly build of DOSBox.
The emulator is 2.2 MB and downloads only when you press Run.
Click the screen to capture the mouse. Esc quits the game rather than releasing the pointer, so leave with your browser’s own shortcut if you would rather keep playing.