Actually I defeated the boss, got the gust gear and thought I was stuck, but now I have finally read the description (as a proper intellectual) and know that that's it.
Even knowing about smash, I still cannot properly execute double jump. Something's weird about it. I was playing on controller and tried on keyboard.
Anyway, very nice game, very cohesive, everything made sense to me. The idea is quite unique, and you probably can do a lot more with it - for example using heavy weight to solve some puzzles, moving platforms down, etc. The visuals and sounds are very nice too. The beginning of the game is a bit overwhelming, but it was understandable. The only thing maybe not that clear was the knowledge system, currently I thought it was a bit unnecessary.
I loled at the first missing boss;) Good job!