http://www.pixelships.com/
PixelShips was originally released for DOS as freeware several years ago. Now the author has a massively updated shareware version that is an absolutely brilliant game! It's horizontal scrolling, and you can switch directions--kinda like defender, but the level design is more akin to the Gradius and R-Type games. The graphics are pure fun (as the title suggests), and the music is great, and there are 160 different ships you can get.
Hey, that game's pretty cool, in an "upgrading my pokeymans" sort of way.
Definitley on my to-download list if Manifesto picks it up.
- HC