Seiken released WiiSPACE for Nintendo Wii.
Quote:
WiiSPACE is an original retro-themed spaceship shoot-’em-up supporting up to 4 simultaneous players for co-operative play. Features include powerups, bosses, high scores, and an aiming system allowing independent movement and targeting.
Version 1.0 was released on 22 June 2009. I’d like to wait a little while before putting this on the homebrew browser (to fix any bugs that might have slipped through the cracks)