Neat little game! I love the delayed explosions upon starting the level. Switching between "building" the level and playing it worked really well. It was fun to solve some levels using fewer bombs than I was given, it would have been nice to have some little award for that. I managed to play through all of the levels, the difficulty curve was nice, the last one was the only one I had to retry (though quite a few of the rest I tried a few bomb placements and un-did them before finally committing). Being able to un-do bomb placements instead of just blowing things up was, I think, also a good choice, made the puzzle more think-y.