The premise of this game is a typical one for IF: You wake up in an unknown room, suffering from total amnesia. What unfolds now could be described as a kafkaesque tongue-in-cheek college humor version of the movie Cube with only one protagonist. Rooms are linked randomly (Spoiler - click to show)- or so it seems at first - and what absurd, confusing rooms!
The puzzles are a blend of combining items, magic and trial and error, though they largely adhere to the logic of the game. The tone is light-hearted and crude at times, fans of toilet humour won't be disappointed, as the game reacts to a multitude of words for bodily functions, excrements and sexual actions, but they are not necessary to finish the game. (Spoiler - click to show)For whatever reason, the author mapped F7 to the 'fart' command. Now that's just silly...
If you like that kind of humour or not: If a game reacts to almost anything you throw at it, that shows that the creator really made an effort and for me, that is always a good thing. You can examine everything and ask the one all-knowing NPC about everything. You can also communicate with this half-philosopher half-lunatic using a menu about a variety of existentialist matters which tends to get tedious at times, but some lines are funny(Spoiler - click to show), like the dialog: "What is the meaning of life?" - "We are manure. Now what?". Makes me chuckle like a koan.
Apart from possible but easily avoidable deaths, there are five different endings that range from religious to self-referential (that one is surprisingly funny). Except for one riddle (Spoiler - click to show)that is just a big hint for the final puzzle in a deliberately incorrect anachronistic style a basic level of the german language should be enough to finish it.
If you like self-mocking puzzle games with an existentialist undertone (existentialist as in Beckett/Ionesco, not as in Nietzsche/Kierkegaard) then give Der Fünfte Raum a try.