Touché
Anyway as far as the game goes, in my opinion the only way this game could work is use the touch screen to control the guns. If they made it into some sort of sidescrolling thing that would epically fail, and if they make it a FPS the controls would be too hard to understand. The only issue is that if they make the contols mostly touch-screen based, which seems to be the most effective thing, the graphics, as HaWk mentioned, wouldn't really look all that great, but you can still tell it's Halo at least. If they try to play the gameplay off as "revolutionary", most people would play it off as a Metroid: Hunters clone, and not an actual Halo game