Did I mention this thread should be locked?
I don't think you did. Maybe you should say it again.
Anyway, I think ghost saves would work better than racing. The problem with racing is that there is a big chance that you'll die multiple times when attempting to complete any level, especially if you are in a competition with someone else. A ghost save is the same as racing someone, but you're racing against their final time, and the ghost would reset every time you died, so it's more fair for both players.