It was great!
I don't know if this was already posted, but second boss can be killed pretty quickly!
WARNING: SPOILER!!!
1. Set the bomb somewhere.
2. Go on the line, so boss, bomb and you will be on the same line.
3. When a fireball will be VERY close to the bomb, activate the bomb. It will take only 5 fireballs to kil, if you are lucky. Fireballs are fast, so it took me about 20 fireballs to kill him.
And about "no life bar"... look down.