Love the game, excited to see where it'll go, all that stuff everyone's said. :) There are a couple things I'd like to see implemented though.
1) In the editor it's possible to see the shadows items cast come down directly beneath them, but this doesn't appear possible in the game. I'd like to have this as an option, since it would making jumping sections easier to manage.
2) A voting system for BBS Levels would be great, of course. What I'd also like is some way to distinguish between levels you've already completed and ones you haven't, so you can keep track of what you've completed.