"Pac-Man" also inspired 3D variants of the concept, such as "Monster Maze (1982)", "Spectre" (1982), and early first-person shooters such as "MIDI Maze" (1987; which also had similar character designs). John Romero credited "Pac-Man" as the game that had the biggest influence on his career; "Wolfenstein 3D" includes a "Pac-Man" level from a first-person perspective. Many post-"Pac-Man" titles include power-ups that briefly turn the tables on the enemy. The game's artificial intelligence inspired programmers who later worked for companies like Bethesda.