The home planet of these people, Iccus, has been taken over by a virus that has mutated into a collection of quite horrible creatures, and every previous attempt to battle them has failed. So now it is Wor's turn to save his home planet and destroy these mutants once and for all!Gynoug consists of 6 levels with no check points, instead you continue right where you died if you have any lifes left. Each level (except the last) has a mid-boss and a large end-boss. There are three types of shots, one that fires in a triangular fashion, one that fires more concentrated in a corridor and a bit to the back and above/below you, and one that fires to the front and back simultaneously. You can power them up in two ways, by shooting more bullets and by strengthening them. Also, feathers can increase your speed like in Gradius.