Maze War (1973) - First 3D first-person shooter

As a foundational Main Game released around 1973, this title is recognized as an early progenitor of the first-person shooter genre. Gameplay involves navigating a tile-based maze using strict 90-degree turns, forward/backward movement, and the ability to peek through doorways. Players engage opponents, seen as 'eyeballs,' to score points, losing them when targeted. Distinctive features include its grid movement system and the occasional appearance of a duck in the passages.