Thank you so much! I found the time quite short especially when you use the bomb, probably you are just more skilled than me. The bomb is definitely much harder to play, but once you master it, it's very useful, especially in later waves. While with the gun, you have to shoot every single enemy, which carries a huge risk of killing yourself in the next round, you only need a few bombs. I usually try to play the bomb in my first life and then the gun twice.