Act 1:
When you reach here, as the boss to rises, jump on either one of them.
After that, stay at one side. Why? That's because, it's the safest place you can find. The boss directly above you would not be able to hit you which only leaves the one at the other side which can throw three small fire balls at you. The're easy to dodge.
However, don't just stand there, do something!!! Keep jumping to hit the boss above you. It should die then. After that, the other boss would slowly descend. If you have the time, go towards that boss and hit it once or twice! Of course, more would be better.
After that, this hand boss would appear.
Stay still at one corner for around 3-5 seconds before running off. The hand should follow you for a while before...
...slamming its hand down. Then, quickly jump onto the hand and hit it.
Soon, the hand would rise and descend down while the first boss comes out again(the remainding one). Do the same procedure and destroy it.
The hand boss would come out again. Do the same tactic on the boss many time thus destroying it.
Midi file for all bosses for act 1 unless stated.
