Binary package “criticalmass” in ubuntu lucid

Shoot-em-up a la galaxian

 criticalmass, aka critter, is a shoot-'em-up in the style of Galaxian with
 very colorful and smooth graphics (provided that you have 3d acceleration)
 Note: criticalmass uses OpenGL, and will probably not run well if you do
 not have a 3d accelerator which is supported by X.