https://mooflu.github.io/critter/critter.html
Use mouse (or arrow keys) to move
Left button (or space) to shoot main weapon
Middle button (or left alt) to shoot secondary weapon
Right button (or left ctrl) to shoot tertiary weapon (only in expert and insane)
p to pause
escape to toggle menu and in-game
(In browser app use backspace instead of escape. escape is used to exit mouse pointer grab)
Critical Mass (aka Critter) is a shoot'em up (smup) similar to Galaxian. The basic idea is simple: you move your ship back and forth at the bottom of the screen, shooting up, while bad guys fly around and shoot at you.
Your world has been infested by an aggressive army of space critters. Overrun and unprepared, your government was unable to defend its precious resources. As a last effort to recapture some of the 'goodies', you have been placed into a tiny spacecraft and sent after them.
