Interesting concept! Only thing that bothered be was difficulty in level design - levels seem to be very easy (except the first one with bats, it was difficult for me to get the grip of it at first), while these levels contain a lot of elements, which seem to be sometimes unnecessary (like the final level with 4 or 5 jumping platforms). Does your game contain secrets which I didn't reveal? Anyway, good job! I would play a full version.