Use meteor for ninja boss on the last level. It's the only way that works. 5 meteors plus one attack from a tower as soon as it comes out. You can also try crypt and hope that it gets scared from fear.
My opinion-based tips: Use mouse to control, it's easier then arrows. For shooting I use keyboard, but you can use mouse or both if you like. Try to shoot main weapon in bursts, holding down doesnt work. First half I used Matt, second I used Natalie. I didnt use any other characters except Lance once to beat a boss. GL and have fun!
Oh there are 26 lvl's. No wonder my cap was not removed :P New players here's a tip: you get the cap removed AFTER lvl 25. I thought it was lvl 24 so I saved the best perks for last. Had a lot of trouble with 25 :( If you cant beat it try using twister with critter to get crits. Then for the FPI people use big kaiser
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