Haha, first 3 days I found Compound bow, sawed-off, reg shotgun, ak-47, and 3 survivors. Easy once you get some survivors. I reccomend the compount bow. :)
I think instead of just using a bigger fireball, you could upgrade your damage enough to where your spark turned into a fireball. I had a little trouble with the mouse movements, I'd cast flamethrower and use tailspin or try fireball and use spark