Xbox Live Indie has a nice few games, all between 80 and 400 points.
Beat Hazard - a space shooter but reads music on your hard-drive to increase enemies/firepower depending on your beat. I have it, great fun beating an 'album' as it says. Is 400 though...
I MAD3 A GAME WITH Z0MBIES 1N IT !!!!1 - Near enough the title. Basicaly think 4 player co-op on a top down persepctive which is highly addictive, very funny and has a great song. There are other enemies than zombies though. Only 80 points.
Breath of Death VII: The Beginning - An 8-bit parody of what is wrong with RPGs these days. Very funny and surprisingly deep and long. 80 points again.
Soul - A very eerie and dark tale which has you guidng a soul through a decaying building to find sanctuary while monsters try to get you first. A challenge indeed. Think of it being the Indie section's version of Limbo. 80 ms.