Arc Squadron from developer Psyonix is an arcade-style space combat game built using the Unreal Engine, so it's definitely a visual showpiece title.
Beyond its great looks, though, lies a visceral behind-the-back rail shooter with a heavy influence from the classic Star Fox series. An intuitive touch control scheme translates your taps, drags and swipes into firepower, barrel rolls, and deft ship maneuvers. The controls are what really appeal to me about Arc Squadron, as it feels like you have real hands-on control over your spacecraft, almost like it's an extension of your finger, and it's much more satisfying pulling off cool moves using a scheme like this as opposed to some plain old virtual buttons.
Arc Squadron was originally released this past October and received a 5 star rating from TouchArcade. The game is normally $4.99 and has never been free before. [Direct Link]