#1: Fotonica
Fotonica is an infinite runner like no other. With a mostly white on black worrisome style, and a first person view with moving arms similar to parkour games, this game is a mashup of elements from many types infinite runners which come together beautifully. This game's visuals and soundtrack give it an echoing and ethereal feel to it. This has beautiful, strange, and abstract music and sound effects. It has three different modes: arcade (level-based), endless, and versus, where to players play in split-screen on opposite ends of the same device. Though this game is about running in a straight line, jumping, and landing, don't dismiss it as another infinite runner. This game is a unique experience, and its stunning visuals, excellent soundtrack, and intuitive controls make it worth every penny of its $2.99 price. You can get it on the App Store. The PC version is in development, but you can pre-order it from Humble or Desura. You can also look at the game's Steam Greenlight page here.
#2: Melodive
Melodive is a beautiful procedurally generated game. In this game, you "dive" into a randomly generated 3D world filled with bright colors and strange flora and fauna. This game is an infinite falling game, wheeler you cannot hit the ground too many times or you will become "out of tune", and then it's game over! The most interesting feature of this game is its procedurally generated soundtrack. The world is filled with little crystals that fly around, and whenever you come near one, it pops and makes an instrumental noise, like a flute note or drum beat. These small crystals are everywhere, and they travel in groups, so you are constantly popping dozens of them as you fall, effectively creating a random soundtrack. The soundtrack sounds more like random noise than music at first, but it grows on you, and adds to the game's open feel. This game gives you a serious feeling of flight and its completely open-world, combined with its breathtaking audio and visuals, make this game more than worth $.99. You can get this game on the iOS App Store here.