Punchball is an orginal 2D arcade boxing game for iPhone. Under the hood, Punchall is using Cocos2d framework for iPhone http://www.cocos2d-iphone.org/, including Chimpunk physics engine http://code.google.com/p/chipmunk-physics/. It also implements such functions as peer-to-peer multiplayer game via Bluetooth (using iPhone's GameKit framework) as well as online leaderboards.