I got assigned to judge this in round 2 of the contest. Sadly it was unplayable on my PC. I don't know why but I think you didn't test against non-QWERTY keyboards and non-standard mice. Not everyone has QWERTY and forcing to WASD means you got to contort the hands on those keyboards. Please make sure the arrow keys are an option in the future.
However the worst was the mouse. I could never do the left click on the crystal after selecting the one item. I dunno if it is because I use a trackball but the system never registered my left click as a left click. I tried all the others to be sure, but failed. In the end I had to mark this as I couldn't play it too far due to being forced in a configuration that just didn't work in the end and being unable to proceed past the opening puzzles.
Hopefully you can fix that for future games.