This is a really good game. I would recommend adding an achievement system (Beat the Game, Collect all the Coins, Fully Upgrade Everything, Destroy All the Robots, Take No Damage, Beat the Game in Fewer Than 10 Tries).
I found a bug. The payouts for the slot machine are wrong. It says the skulls pay out at 40:1 and the mugs of beer at 150:1, but the actual payout are reversed. The mugs pay out at 40:1 and the skulls pay out at 150:1.
Is is really multiplayer? My user name was on one of the things running in addition to the one I was controlling and the my best run one. Does it just use motions from past runs to make it appear as though it is multiplayer?
I'd be ready to add badges... it's just a question of the game rating ;)