I must say that I love the music. It has that catchy yet somehow cartoonish tune. At first, it might look like it isn't a serious project because of the appsrently fast drawn art, but when u play it, u know it has a lot of stuff "that actually works" and feel connected to a very unique style.
From the transitions, to the bouncing bullets, to the secret areas and dialogue, I must say, this is done by a guy that knows what he is doing. And I'll add that I am envious of your ability.
Keep it up, this looks really cool, and it's pretty funny how the 'subtle' messages are given too. Really creative!