We (2 friends of mine and myself) recently made a large neo-retro pixel-based video game akin to galaga, robotron, etc. It took us about 8 months. It's got lots of weapons, characters, bosses, etc, and a full 8-bit soundtrack as well. We are giving it all away for free.
The Link:
http://www.pixeljam.com/gammabrosYou can get some screenshots and download the thing at that address.
Please check it out and let us know what you think!
but rather BIG (19mb) for a pixel game