Stumped, as if by a petard. My own, at that.
I've been working on Switch 2000, and I finally ditched the old abstract tileset. Now I've got the capacity to use arbitrary images, and the game's substantially harder. Doing the math (because appearantly, I love the math), with the abstract tiles, there were over 300,000 correct solutions to a 4x4 board. And now there's only one.
Check it out:
Check it out: