Click on the green flag to start. Use arrow keys to move. All levels are possible. Good luck getting out of the void! Also, you can wall jump, though really, you don't need to for any of the levels. You must collect all of the coins in each level to proceed. If the portal is black, that means you haven't got them all. If the portal is white, you can jump into it to proceed to the next level.
Thanks to griffpatch's scrolling platformer tutorial for around 80% of the code. All levels by me.
