Stupid Invaders

Stupid Invaders (French title: Les Envahisseurs) is an adventure game that was developed by Xilam Animation for Ubisoft Entertainment and initially released for the Microsoft Windows operating system in 2000, but later ported to the Sega Dreamcast and Mac OS in 2001; it's based upon the developers' own animated series Les Zinzins de l'Espace (which originally aired on France 3 when they were part of Gaumont in 1997, and is known as Space Goofs and Home to Rent in English-speaking countries).

Story
This is taken from the back of the discs' inlay card, the front of which is seen in the image to the right:

The game features the voice actors of the series' English dub: Charlie Adler as Candy H. Caramella, Jeff Bennett as both Bud Budiovitch and Stereo Monovici, Maurice LaMarche as Etno Polino, Danny Mann as Gorgious Klatoo, and Billy West as Bolok the hitman (but all its other characters are voiced by Rob Paulsen, and Laraine Newman, both of whom did not have any involvement with the series).