I just picked up a Porcupine puzzle, anyone know how hard it is?

http://home.attbi.com/~adler/porcupine.jpg


I guess its available from http://www.toysinternational.cc

Ah, a great puzzle indeed.
I got one of these not too long ago and figured out how to solve it on accident. It's kind of tricky in the conventional sense. I don't really want to reveal the secret or anything, but the solution wasn't what I was expecting.

-d