People need to read the game info. the balloons are filled with water AND helium! duhh. Don't ask why. Just go with it. Alright game, but I think it needs too much patience to not just pop all the balloons on the ceiling and drown the guy for fun.
Obviously many ways... HORRIBLY repetitive gameplay, no story line (how do zombies get shields?), so story mode is a bad idea, and if you don't click on the start mission thing, you can just go around without using any fuel unless you use your chainsaw, as long as you don't click it. You'd have to be an armless parapalegic to lose this game.
I was just playing for about a half hour after I killed the boss monster... I didn't realize i was on the card thing, so I couldn't see the check mark :-\ The boss is WAY too easy, in fact, i fought two of them at once and killed them both easily.
For the people who are offended by the amount of blood... COUGH XKAT20.
You probably should have quit at the frog exploding, rather than beating the game.