Cosmic Guerilla is a fast moving arcade-type game. Contrary to the note on the cassette insert card, there are no on-screen instructions but it is not difficult to play. Key 6 moves you left, 7 moves you right and 0 fires. The speed of play is selected for a choice of three - I preferred the fastest of the three, action is very smooth and responsive at that level.
The object of the game is to defend your city from marauding space guerillas - you shoot them down from your ship, which moves along the base of the screen. As you knock out the raiders they leave their plunder littering the skies. As this loot is impervious to your missiles and remains in the sky, it becomes more difficult to shoot at the guerillas as the game progresses.
These guerillas are not just sitting ducks, they are programmed with some 'intelligence' and do not fly into your missile tracks. They therefore can be quite difficult to destroy. I got rid of the first batch without too much trouble but the problem is that successive armies appear. A score card is kept and the game ends with the loss of all three of your lives.