Very cool! I keep fingerslipping, but I'll get it soon. I agree with Diablillo on every count, except there actually is a 2-off. This is also an interesting application of some familiar things. Plus, I like how such a symmetrical level has such an asymmetrical solution. You should submit this.
theres actually 2 or 3 small optimizations along the way that could have been implemented but weren't. even though the general path is the same, theres 3 variations on the solution.
Insights