The $0.99 retro-styled game has been getting high praise in our forums for what is a relatively new game mechanic wrapped in a very nice package. The idea behind the game is somewhat similar to Upsi Looper (no longer available), but thankfully implements touch controls rather than tilt.
In Spirit you move your ship around the screen by simply tounching any part of the screen and moving around. The ship moves relative to your finger so it never has to be in the way. The goal is to destroy the enemies by looping them with your ship's trail. If successful, a vortex appears sucking them away to nothingness. Combos and chains improve your score, and all the while you need to avoid running straight into an enemy.
Check out the developer video:
Learning to move your ship accurately is a bit of a challenge, but in that "gotta try one more time" kind of way. The gameplay is also further enhanced by a great visual style and sound effects as well as a good variety of enemies. At only $0.99, if you're looking for a challenging new arcade experience, this one's easy to recommend. The current version does not have global leaderboards, but the developer has indicated Open Feint integration is on the way.
App Store Link: Spirit, $0.99