Do this achievement alone! On a completely different playthrough from the other achievements. When you see a green glow you will know that a bomb will come up. Your weapon can not touch them but your body can so when you see the green glow come up(a little towards your screen) , move away from it and stand completely still with your hands in the air. That way either your weapon is high enough to where it will not hit the bomb or is even off the screen. If you don't move your weapon then the bomb will not blow up. Except on level three (Michelangelo) where you have nunchucks. The nunchucks will always move around so even standing still the bomb's will blow up when it hit's your weapon. So everytime you see the green glow you should move as far as you can and put your arms in the air (this will still help you in not hitting the bomb because most bomb's will not go that high, but you have to have some luck on your side).
Use these so you know when you can take a break and slow down.
Training level - 0 bombs
Donatello level - 4 bombs in the main part.....0 in the pizza level
Michelangelo level - 4 bombs in the main part.....0 in the pizza level
Rafael level - 1 bomb in the main part...1 in the pizza level
Leonardo level - 2 bombs in the main part....1 in the pizza level