Hi there, thanks so much for being the first commenter!
The rooms after the 'fast forward' are part of the end game. I wondered if the difficulty was going to be too much when juxtaposed against the tutorial/intro, but I didn't want to show the other game locations *just* yet. The final game will have a concept of 'shields' to give you a bit more leeway with failure on the tougher rooms.
Chain climbing - you're right. The tutorial for that part was a casualty of cutting two parts of the game together.
This has been my sole project for the five years. A *ton* of time goes into the story cinematics. It's already taken at least two years longer than I thought, but might as well try and do it properly.
Thanks again! Comments like this really give me a boost :D