You're on the run. Your attackers are relentless robots. Destroy one and it's replaced by an even smarter, faster robot. It's a nightmare. Your only defenses are avoidance and weapons found somewhere in the labyrinth. When one weapon empties, you avoid robots to find another. Duck around a corner or go into your safe house. But, be careful. There are also people-size spiders and their webs to slow your escape. Bats also wing their way at you. If either spiders or bats bite you, you're stunned; easier prey for the robot attackers.
Your man is trapped in the maze. Robots relentlessly track him down. Keep him away from spiders and bats. Watch out for robot fire! React quickly. The key to survival is to destroy them -- before they get the man! Rack up as many points as you can! It's you against them...to the end!
Nightstalker is largely inspired by Berzerk, with its maze and agressive robots. But here there is only one room to play, though the ennemies constantly become harder to beat.
Move around the labyrinth avoiding or shooting spiders, bats, and robots. Prior to be able to fire, you must pick up the gun that will enable you to shoot six times. After that, another gun will appear randomly within the maze.
The Aquarius version is quite limited compared to the Intellivision game.