great job on this. Well done!
Bit to much frustation at times for me :P, but that's more to do with me being rubbish :D
Intelligent puzzles, just maybe a little to complex to early. Little more hand holding and learning early on would have helped.
Well done!
(oh and try mine out, it's a similar mechanic to yours. I've lernt from playing yours, and it'll help me with evolving my own. Perhaps playing mine will help you, i dunno :P)