The bits of story in between gameplay was a nice progression, I could see how this would continue.
I like that the bunny pop can spiral out of control. I think there's an opportunity for a mechanic that gives the player greater ability to deal with a pop explosion (grabbing more than one at a time, or more than one bunny per cage etc.)
Currently, you can end up with more bunnies than cages and it becomes impossible to win.
A larger play area may allow for a faster moving player that wouldn't feel as restrictive.