At Doom's gate intensifies

DOOM video game series was started on 10th of December 1993, but developing of the first DOOM game began on November 1992.
The game introduced 2,5D graphics, networked multiplayer gameplay and players' made mod support in DOOM WAD format.
Game consists 3 episodes, each episode has 9 levels, one of them is secret level, which's entrance is hidden.
On year 1995 id Software released The Ultimate DOOM, which added fourth 9 leveled episode.
The developers of the game are John Carmack, John Romero and Tom Hall, but there were more important people working on it, for example American McGee, Adrian Carmack(not associated with John Carmack), Sandy Petersen and others.
The composer of legendary DOOM OST is Robert Prince.