itch.io

did you check under stuff, some are hidden like that. or around lone pillars.

I found 28 so far. I don't know what that purple plate is either.

yo, did you know (which you wouldn't cause it didn't tell you) that you can backflip? 
get moving, then snap to the opposite direction and jump. wall jump, then dash back, and you should make it. give it a few attempts.
edit: oh, apparently there is a climb button. didn't know that.