Thanks for great feedback!
I absolutely agree that level with a "button" and second last level are harder than others. Without any playtesters it is hard to understand the true difficulty of the level. Ideally we should've made more "transitional levels" so players could get used to new ideas.
We had many problems with the "dash" mechanic: it was supposed to be an "endgame" feature but players were randomly dashing through blocks and softlocking themselves at earlier levels. Personally I don't really know the solution to this problem, maybe earlier levels don't need this feature at all and it should locked away with code.
Anyway, I'm glad you enjoyed our game, even with its many flaws