Space Attack is a 1-player arcade game for the VIC-20.
The player controls a small vessel at the bottom of the screen that moves horizontally and fires vertically. Numerous alien vessels approach from the top. These vessels move side to side, and fire angled and straight shots. The player gains 10, 20, 30, or 40 points depending on the ship destroyed. Progressively faster aliens appear as the game progresses. There are 3 skill levels, and the player has 3 vessels each game.
Space Attack is a shoot 'em up that mixes elements from a number of popular arcade games of its time. The player's task is to defend a city which, like in Missile Command, occupies the bottom part of the screen. The city is being attacked by aliens unleashed by a feared warlord who aims to fully destroy it. The aliens attack from above and move around in patterns similar to fixed screen shoot 'em ups like Galaxian. They drop bombs on the buildings on the surface and the player has to shoot them down before they do so. Controlling the spaceship is similar to Asteroids, with a combination of thrust and rotation allowing it to move all over the screen and shoot in any direction. In addition to the regular fire, a super weapon can be used but it's limited to three uses. Another thing to watch out for is the fuel level of the ship. It's necessary to land and refill it before it runs out.