Tetris Effect has a brand new theme that is free and looks absolutely stunning. The name is more than appropriate as well - Metamorphosis. Not only does this theme look beautiful, but it's highly dynamic as well.

A YouTube user RenkaWong has posted an official clip where you can see first-hand just how epic this theme is (first-hand).

The Metamorphosis theme certainly is certainly one of the most beautiful themes in the whole game. And if you didn't play the game before, hopefully, this will inspire you to do so.