A most excellent Atari arcade game in which involves three floors and up to three players simultaneously, hunting down icky slimey aliens on space stations.
I played this game the most on Atari Lynx, and actually beat it once with my friend Phil. I couldn't use my thumbs very well for a while afterward, though.
One of the best things about the Lynx version was that you could play as one of the Snotterpillars, and go around killing the other players.