Concentric Chaos

In addition to what everyone else is saying, there's lots of little things, like the shapes contrasting with the background, and the music automatically turning off when your playing something in the background.

At first I thought that this game was really weird and confusing, but once I got the hang of it, it started to become really fun. The variety of difficulty settings is really nice, the sound effects and music are pretty good, and the idea is really creative. The fact that there are no ads is also really great, because ads are the reason why I usually stay away from mobile games. I don’t have an unskippable 30 second ad pop up every 2 tries like with other free mobile games. With more polishing, I can see this being an amazing game.