Coming along well
The controls are smooth, the physics work nicely, and it looks like this is going to be a very fun game. Some suggestions I have for the final product include a way to attack (unless it's a hop & bop, but some other attack would be a welcome addition), additional interactive elements if you think you can use them (you got switches so far, that's good), and a neat presentation that lays out the levels, menus and stuff nicely (although I'm sure you're already working on that).
Not much to say, really! Just give it an identity to make it unique and interesting, and I'm sure it will be great. I must say that I'm intrigued to see how this will end up.