“Berzerk” for the Atari 2600 was one of my favorite games in the 1980’s. It wasn’t exactly high-concept … you shot at robots who shot at you, in a series of redundant maze configurations. To mix things up a little, both the robots and the walls were electrified, so you had to make sure your little monochromatic avatar didn’t touch either.
The more difficult levels added another threat — a giant happy face (like the famous 1970’s t-shirt design) named “Evil Otto.” It … sort of bounced through the maze, and was also electrified.
“Berzerk” was an unusual game, too, because you could take a break from it. The game didn’t have a “pause” function; the Atari 2600 was far too rudimentary for that. But if you killed every robot in a room, you could just allow your little guy to stand there before walking him into the next maze. You could get up, go outside and play, call your mother from the landline, or make a peanut butter sandwich on toast (considered a delicacy at the time.)
If you want to play the original “Berzerk,” you can play it for free right here over at Virtual Atari.