Super Polygon.

Super Polygon is a twitchy, hypnotic music-rhythm based game that looks deceptively simple but is hard to master. This is the game you need to zone out and lose yourself in the minimalist action mechanic beating to the music. Your reflexes and patience will be tested. You will get trapped in complex polygon patterns, repeatedly die and get frustrated. But you will rejoice when you figure out the patterns and how to navigate the treacherous polygon world. So zone in or zone out... and get ready for addictive gameplay.
First check out the tutorial/learn mode, choose the visual theme you like and then get down to it. Prove yourself in Super Square, Pentagon, Hexagon, Octagon and Shape Shifting Polygon modes to put your best score on the online leaderboard.
Super Polygon is free to play, you can unlock each level by completing the previous level. If you want to make it easy you can make an in-app-purchase to enable early unlock which will reduce the level unlock time to half. You can also enable full level unlock and remove ads using in-app-purchase.