I hate the "Games as Art" argument, but when a game manages to look and sound like Contre Jour, I kind of have to jump into the argument feet first. Contre Jour's look is every bit as mesmerizing as its gameplay. The monochrome color palette creates a beautiful world that is easy on the eyes. At the same time, it is hard to not get pulled into the world, especially in later levels when the black and white world is transformed into a black and neon blue wonderland.
If you own a pair of headphones, make sure to use them. The subtle soundtrack sounds okay through the iPad's (or iPhone; it is playable on both) speakers, but you really need the power of a great set of headphones to get the full effect. The music creates a relaxing mood that works well alongside the visuals and almost zen-like gameplay.