Long-lost PC Game

Hi, I'm looking for a PC game, probably came out in the last ten years or so. It was for Windows called "Chain Reaction" or something similar. It had about 50 levels and it was a strategy game-you had to figure out how to blow up the red atom in the game, I believe. You could only get to the next level if the game gave you a code, I think. I know one of the primary colors of this game was gray and since that's an odd memory it's probably right. We thought it was marketed by Popcap or Bigfish or some such but none of us can find it on their lists. Please help!