Along with some of the other suggestions, I would ask you to set it so that the level starts out on the block mode or automatically resets to block mode. That way you don't blow the level before you even start.
I'm not sure the submission part works either. I clicked it several times and nothing happened.
Lastly, someone else mentioned gridlines, I think that would make it too easy (I thought it was easy to begin with).
Polish the game up and you'll have a winner.