Key there, thanks for your reply. A tutorial was out of the question given how little time I had left when I was finished, but I get that the controls are a bit long to get used to. About that door closing, I think you're talking about the final door : Each final door requires you to collect a certain number of coins (displayed on screen). If you don't have it, then the door won't open, which is part of the challenge of getting the best time while also collecting as many coins as possible.