I saw Chillingo's new game Contre Jour back at E3 this year, and really enjoyed it. It's a very atmospheric puzzle-platformer in the vein of games like Cut the Rope, but as you can tell from the title (which is French for "against daylight"), it's a little darker than that game. You run an eyeball named Petit around a strange little world with stalks for him to swing on and bulbs for him to stick to, and the black and white graphics and great sound design perfectly set the scene.
There are sixty levels to play through, and nearly all of them are inventive and fresh. Contre Jour is a really solid experience -- it's casual enough for all players to pick up, but it never gives away that quirky art game feel. Really well done, and a great purchase. Game Center achievements seal the deal.