Yeah I think I really did click on the selected block to attempt to unselect it. I was frantically trying to unselect it using different methods for a whole minute before just giving up and watching the game slowly end. Which was actually nice cause I got to see a bit more of it, the most time is spend looking at the left. And the nice portrayal of the underworld on the right can sort of be ignored. I suggest you also just disable a block that can't move any direction? Maybe give it a a little shake and a soft *kegh* sound when you try to click it anyway. :)
Audio worked just fine.