Hello. I like your game and I read that you did not have sufficient time. Really you have a good game idea, but the tutorial is no so clear and the big problem are your controls... press ctrl or shift is an error in a game, because these are keys that generally are used for diferent functions in a computer. In the game, in a few times, I pressed ctrl or shift and my computer open a new window or it asked me If I want  to save the page or It did other actions. Because of that, I advice you that change your  controls. In the rest, your game is simple, needs improve but I think it is nice and the music are good.