Parasitic mushrooms invaded from space, spreading all over the Milky Way. Since humans are long extinct and vegetables rule the earth, this should no longer be a problem for you... But surprise! It is you who must stop the invasion.

Join the Aveggers aboard their space cruiser Sail-Trek and travel to planets throughout our solar system to defeat the head mushroom honcho, Satanus Boletus.

It's not going to be easy, but as brave carratado, joined by General Despotato, scientists Nicola Siesta and Garlic Alistein, you might just be able to do it.