Wow, thanks for the feedback! Truly, it's a huge help
Your comments about the overall fun of the current gameplay loop are right on the money. Figuring out how to take these basic mechanics and turn it into an fun game is going to be the hardest part of this process, I think. I'm good at programming, and sound design, but game design on anything larger than a game jam is a new experience for me.
I've added your suggestions to my pile of game design ideas. Now it's time to try a bunch of stuff out and see what people enjoy. I think the next step is to make demo levels in different styles and mechanics and see what works.
-Ken