Once upon a time, a very smart publisher came up with a brilliant idea. It contacted Microsoft and got the ball rolling on a very unlikely project: Halo for Nintendo DS. Needless to say, there were many egos involved and unfortunately because of some issues that I won't detail, the project was eventually cancelled. But not before it was completely up and running and fully playable. I know all his because I recently learned of the back-story and got a chance to play a leaked build of Halo on DS for myself.