TPG writes: "Gravity Sling is one of the first games to launch with in-app DLC being the revenue generator. You get 15 levels for free, but have to pay for 30 new levels for only $0.99. We could have philosophical arguments about what this means for the App Store until we run out of bad metaphors to use, but it wouldn't mean anything unless the game is any good – thankfully, Gravity Sling is pretty fun."
