I don't have much to go on, this was a childrens' game that featured cartoon alien characters and the opening scene (when you booted the game) was a funny short involving these characters taking a roller coaster ride through space or something, and the game itself was I think a freeplay where you completed various missions, one of them for instance (because I don't really remember the others) was a maze game where you navigated one of the alien characters (as each was assigned to a mission I think) and had to occasionally collect oxygen/water to top-up their supply or the mission would end.
The graphics were 3D. One thing I do remember is the drawing style of the characters was very similar to Purple & Brown, when I saw this animation I thought it had something to do with the game!
Any help appreciated on this vague account