When people think of the Golden Age of arcade games, they picture Pac-Man, Donkey Kong, or Space Invaders. Titans like Atari, Namco, Nintendo, and Midway ruled the arcades — but they weren’t the only players changing the game.

Beneath the flashing lights and coin slots was a pack of bold underdog developers pushing boundaries. Let’s plug in and explore the forgotten trailblazers: Gremlin, Centuri, Universal, Exidy, and Stern.