Thanks for the feedback.
I must say, this is just some kind of "test" level for the jam. When working further on it, the game will change. The main mechanic with switching the worlds will stay and defines the game. But the level itself will change and also there will be more affect in game, when switching the worlds. Even thought about something like platforms appear, which could not be used beforehand and more.
I thought the small tutorial, which was kind of a little dirty programmed, was necessary to explain the main mechanics, otherwise it wouldn't have been very clear why these enemies can hit you, but you can't hit them. And to explain the main mechanic of the game a little.
Thanks for the compliment :)!