Classic DOS FPS
Doom
The 1993 original, running in your browser through DOSBox. Click the screen to grab the mouse, then rip and tear.
Mouse look & shoot · ←↑↓→ / WASD move · Ctrl / Click fire · Space use · Shift run · 1–7 weapons · Ctrl+F10 release mouse
First load downloads the emulator and game (~4 MB) and caches them. If the screen stays black, click it once and wait.