I kiiled Sven, don't know if that's the only issue, and don't want to retry as I already reran the game after trying to take a nap when Sven gave me the chance. That's probably why I killed him, because he killed me in another time.
The 2x2x2 room was quite tedious but really cool.
I don't know if there's a clue for the 3 switches or if one should brute force it, I found it randomly.
I wished I knew which door was to be opened by the next key.
I liked it !
Ah, and the music stoped, that's cheap, you could have looped it.