Let me give you a universal design tip:
If time isn't a key factor, the game shouldn't consume the players time idly. For you game this applies to the moving platforms. On some levels you spend most of the time waiting for the platforms to come, even though you would like to proceed.
And some bonus not-so-universal tips:
Do not use a wall with rather noticeable holes in it if you want to put spikes on it. This makes the spikes look like they are floating which is strange.
Also, I don't get why you do not move with the platforms even though you are standing on it. :/
Other than the few problems I mentioned above, the game was pretty fun, with visuals that match together well, and a nice main mechanic. This turned out nice.
P.S. Since itch.io refuses to show our submission under my comments: https://itch.io/jam/brackeys-3/rate/569748