criticalmass 1:1.0.0-1.4ubuntu1 (amd64 binary) in ubuntu natty

 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.