painkiller help

Ok, the boss I am at is after the haunted town which is the level after the bridge thing...you can't go into the water/sludge/dangerous stuff as it hurts you...I have not figured out how to damage this guy...I know you can shoot the huge ball of crap he flings @ you and you can dodge the hand that he makes come out of the ground...but no matter how much I shoot him, his health does not appear to decrease...can anybody help me?

 

This is the swamp creature boss, right?

As he walks around the level, you should see these huge gas bubbles form around the swamp. When he walks over the gas bubble, shoot it and blam! It should do some small damage to him. after a while the bubbles will all be burning, and then you will have to shoot the flying bubbles when they pass near him to do damage. Then, after a bit more of that, he'll go around putting out of the fires, and at that time you can just wail away on him directly. Once he extinguishes all the flames, then you have to start the whole process over again.

I hope that helps.

 

oh boy..this is gunna be fun