Why isn't this front page yet?
I invested early in scavengers. Really early. It made my life a living hell when I was using a Mac10 on wave 25, but IT WAS WORTH IT. By the end I had the fully upped minigun, every other gun, every non-weapon upgrade maxed out (builders, armor, aids, that other one, assistant, scavangers), without going through it a second time.
It. Was. AWESOME. You rarely get anyone who nails the risk/reward system as well as the Bunny Invasion series does, along with cheesy-fantastic dialogue and simple joy of slaughtering waves of adorable fluffy animals. Thank you, good sir, for making another great game.