Fun game! I'm probably going to jinx it now, but after about 10 games I'm undefeated. 😛
I do have a minor bug report, but I can't replicate it on demand - a couple of times I've hit the X key to place an atom in a spot that already had 2 atoms, but then the spot suddenly exploded as if I had placed a 4th there. I think sometimes the game is reading the key press twice during the same frame or something like that. (I actually won once because of this - which was lucky - but probably it shouldn't have happened.)