Doom

Doom is a first-person shooter developed by id Software and released as shareware in December 1993. It didn't invent the FPS but it defined the genre — 3D corridors, fast movement, ferocious combat against demons of Hell, deathmatch multiplayer, and a modding scene that persists three decades later. Doom (2016) and Doom Eternal (2020) revived the series with acclaim.