Eli Hodapp reviewed the Moga Ace Power, the first game controller to hit the market for iOS 7 devices, for Touch Arcade:
There’s also an odd divide between games that can use controllers and the platform they were originally designed for. Oceanhorn], for instance, uses the controller but it seems like a vast majority of the game is played just using a single button and analog stick, leaving the rest of the controller feeling weirdly unnecessary, especially when Oceanhorn is a game that worked so well on the touchscreen anyway. Games like Bastion that were originally built for controllers, however, are amazing when played with the MOGA Ace Power. All the clunkiness of the virtual controls fades away and you’re actually having fun instead of being frustrated that your right thumb migrated off a virtual button. Tactile feedback means so much in games like Bastion that it’s hard to go back playing it “normally” once I took my phone out of the MOGA Ace Power.
Eli is clear that this controller can’t compare to PlayStation or Xbox controllers, but it is an important first step. This, also, is important:
…it eats up the Lightning port, and while this might not seem like that big of a deal initially, it kills the potential for using your iOS device as a game controller on a TV. The latency introduced through AirPlay is substantial, and I can’t imagine anyone playing a game on their TV via AirPlay using a controller for anything past the initial “Huh, well that’s neat,” sensation. It’s “playable,” in massive air quotes, but isn’t a great experience by any means.
A game store can’t come to the Apple TV soon enough.