No pun intended - I am actually not sure, if I can or rather am allowed to write the international title of the movie, without the review being dismissed in and of itself. Hopefully curse words are not an issue with you - or the literal meaning behind them. Because this really goes places (actually one in specific), that is surely not for the sensitive ones amongst us.
All that being said, this is a genre movie from Germany. Very low budget but also very inventive and very well done. And such a joy to watch - although some may disagree with my use of the word joy here ... especially the main character. But first things first.
This is a one location kind of movie. And while many may think that it is easy to shoot a movie like that - in reality it is as difficult, if not more difficult to realize and make it interesting for audiences. Watching this movie though, it makes it feel so easy ... to say the least.
We start with a sequence that is ... well let's just say dreams can turn into nightmares. One thing you have to be aware of: this is not medically "cleared". Obviously you shouldn't try anything the movie depicts (at home or in one of those toilet boxes), but it's also evident right from the start that the movie will be quite heightened.
The lead actor who is an unknown to me, was very well chosen. And while we always talk about Scream Queens, he could at least be a Scream Prince! All kidding aside, he has to go through quite a lot and Kudos to him - because he remains likeable throughout. There are some moments where you might question his (people) judgement, but never his decision making. I would even go as far as to say, he thinks of things, I am not sure I would have thought of.
Convenient placing of things aside (although not too convenient or comfortable), there are many good ideas in this - and according to the director everything they thought of made it into the movie. Tight scheduling, amazing lighting, a song that you may love to hate (classic in Germany by Münchner Freiheit) and lots of fluids and ... "stuff" thrown at you/the main character.
So if you love low budget movies and are not easily offended, go out and watch it (playing in Germany in cinemas right now for a week!) - it is worth it! It is a win/win for everyone.