Skyward

It may look suspiciously similar to the wonderful Monument Valley, but give Skyward a chance (it's free, after all) and you'll see that it offers something quite different. You control a red and a blue circle, and have to rhythmically guide them through Escher-like levels that are falling away behind you. Take too long, and the circles shrink to nothing. It looks fantastic, and there are no in-app purchases, so you get the full experience for free.

credit: androidpit.com
https://play.google.com/store/apps/details?id=com.ketchapp.skyward