Berzerk Imitations

Berzerk first challenged you to pick off enemies in an open arena, and other games took it from there.

Robotron 2084 - Robotron 2084 removed the walls and the exits, putting the action in a completely open battlefield and forcing the player to defeat all enemies before moving on. Players also gained the ability to walk and fire in different directions, thanks to the game's two-joystick control scheme. Humans to rescue further added to players' strategies. The differences were enough that Robtron 2084 became far more successful than the game which inpired it.

Smash TV - Robotron codeveloper Eugene Jarvis then worked on this game with a similar theme. This time the player is a challenger on a futuristic game show, where survival is rewarded with souped up weaponry and fabolous prizes.

Total Carnage - This sort-of sequel to Smash TV features a cameo by the that game's hero, along with even more open-air mayhem.