Just found two wicked indie shoot-em-ups.Check them out:

• White Butterfly
• Garden of Coloured Lights

Both work fine under wine and offer some smooth minimalist eye candy and great game mechanics. Check out especially the weapon system of Garden.

Some older findings in the field of shmup minimalism are the games of Kenta Cho, some ported to linux. Rrootage and Noiz2sa are my favourites.