https://ellisjames20061.itch.io/level-switch
You play as a cube that has the ability to switch the level. You must keep switching the level to make progress encountering different enemies and obstacles along the way.
There are two variants of the levels. The calm white version and when you press s to switch the level you are thrown into the alternate evil back version. The only way to get through this game is too keep switching between them in order to reach new platforms or dodge the enemies blocking your way.
When you reach the end it tells you some stats llike deaths and how many jumps you made during your playthrough.
Source: itch.io