Cosmic Bugs

From the book "Commodore 64 Games Book". In this game creatures attempt to get from the top of the screen to the bottom where they turn into Crabs which close in on you. You defend yourself with a blaster that can fire nets or energy blasts. Nets trap the creatures and earn you double points, energy blasts kill them but sometimes only split them in which case you only get half points. If the screen turns yellow you must prepare to move your blaster as it moves up the screen to the top, once successfully at the top the game will resume in a new play area.

The creatures are:

Scorpions — These are red and worth 10 points for a kill.

Spikers — These are green and worth 20 points, or 30 when they leave a spike behind.

Cutters — These are blue and can free other creatures from nets. They are worth 40 points and cannot be netted themselves.

Crabs — These are other creatures who have reached the bottom. Your only method of killing them is to use the super-zapper, (space bar) this uses 25 points. The screen is grey when you have enough points. The first time it is used it kills all life, otherwise only crabs.