Scrolling the only thing keeping you from a Sencha / Phonegap like approach?
Jittery, slow, and inconsistent scrolling and page transitions were (sadly enough) the thing that made me just go with Objective-C.
The native app, by comparison, is clearly significantly superior. I wish it wasn't so, but it is.
For games at least, I'm convinced native is the way to go.
Alex, congrats, the game turned out beautifully.