Thanks for playing all the levels! Yeah it's bit too much for a demo. It's pretty much a playtest at this point. Originally I planned for like 40 levels but it just kept growing haha. I plan to release a proper demo with a more focused set of levels.
Yes I also feel that lv35 is hard to understand at that point in the game. I added it to build up to the fold entry ability but it's hard to understand before entering folds. I plan to make it easier to understand and/or updating the level in the future.