Well, I think that all feedback is valuable, no matter if it's from a stranger from the internet (which also counts for basically everone I don't know personally :D) or a friend. As long as feedback is more than "your game is shit" I appreciate the feedback, so thanks for the feedback!
I'm done with most of my feature reworks and I am restructuring the tutorials now. When I get to the blocker level I will see if I can make it better. What I don't like right now is that the main tutorial, the human bouncing on the trident and flying into the lava is quite easy to miss, so I will improve this someone anyway.
I will keep an eye on the missing music, can't really explain how it could vanish but would not be the first bug in a game :D