I know its not exactly a game (although you can level up and there are unlockables) but it's a great app and has the potential to fight off the dreaded gamer gut (is that even a thing?). http://itunes.apple.com/app/fitfu/id403701162?mt=8
Fitfu est a great fitness game which help you to get in shape. Here is my referral link: http://www.fitfu.com/i/email/referral?u=Seblitz Each time you do an exercice, you gain points. These points can be used to unlock new exercices. This concept is very interesting and help to stay motivated.