A 1983 Silversoft computer game for the ZX Spectrum.
The basic premise of the game is to steer a snake, Slippery Sid, around a screen without hitting the walls or hitting Sid's own body. The object is to eat all the frogs, but to avoid the toads. For each frog eaten a toad appears and Sid gets a little longer. When all the frogs are eaten the level is cleared. Later levels are harder as more walls are introduced. Occasionally a mushroom appears which, if eaten, allows Sid to eat a toad.
This is a cracking, simple game and was one of the few games which my father would actually play. I wrote a version for the SAM Coupé in the late nineties but I never quite finished it as feature creep set in.