Halo Zero is a freeware computer game. It was created in 2004 by Dobermann, but is not endorsed by Bungie or Microsoft. It is a side-scrolling shooter and is based on the Battle of Reach. Some say it was bad, some say it was good. It's non-canon. It is free and you can find it by Google/Bing/Yahoo searching it because it's site was deactivated. It is fun and is easy for most computers to run.