Finally got around to playing this, and it's looking pretty good so far. The tilework is awesome and the controls are responsive, even with the inertia.
I only have a couple crits:
1. The jumping seems a little too linear. Like an inverted V, it's pointy on top. There doesn't seem to be any deceleration/acceleration at the peak of the jump which, makes it look a little odd and jerky, especially since the horizontal movement has so much inertia.
2. I think it's just the expression on her face, but the girl kinda looks like a mean old man in a wig. It's the heavy brow and small eyes. And I know the cheeks are supposed to be chubby, but they look a little jowly. I don't mean to offend, it's just the impression I get looking at her.
But otherwise it's looking pretty slick. Keep it up!