tl;dr: Developers at CedarDB ported the original 1993 Doom's game logic and renderer entirely to SQL (~5900 lines for logic, ~1300 for the renderer across 89 CTEs), with Python only handling input, timing, and bitmap display. The implementation hits the original 35 Hz tick rate and renders up to 60 FPS by exploiting BSP traversal via bit-packed sort keys, window functions for visplanes, and brute-force depth resolution via min() on packed bigints. Multiplayer deathmatch comes nearly free from the database's built-in authentication, transactions, and access control, with a public playable instance available.