The Powermanga website boasts:
Powermanga is an arcade 2D shoot-em-up game with 41 levels and more than 200 sprites. It runs in 320x200 or 640x400 pixels, with Window mode or full screen and support for 8, 15, 16, 24, and 32 bpp.
And I must say, it's a beautiful game. The theme is pure retro art deco transformed by some alien design sense.
To install Powermanga:
sudo apt-get install powermanga
It works well enough on my unaccelerated video card, so you should get good mileage out of it, too.
Just some tips, as the controls aren't so clear from lack of in-game documentation:
Other than that, it's shoot! dodge! shoot! Great mindless fun.