Jeff Minter's new Xbox Live Arcade game Space Giraffe is brilliant. It's nominally a Tempest-like shooter with some gameplay subtleties. But what it really is is completely fucked up. If you have an Xbox 360 check out the demo. If you don't, this video gives an idea. comparison to Ulysses. A bit impenetrable, but deeply rewarding.
I love Xbox Live Arcade; they're cultivating a catalog of inexpensive games with creative visuals and fun casual game play. A game like Space Giraffe has no hope as a traditional release, but as a $5 Xbox download? No problem. Lumines is also brilliant on XBLA and GEON: Emotions looks promising.