Boring, repetitive crap in place of levels. Imbalanced shop. Weak, 1%-kind level up upgrades. Illogical and expensive skill tree. 2/5, and only because I love Berzerk's art.
Besides endless grinding of truly epic proportions (has anyone mention that yet?) I must note that the end was THE MOST D__NABLY ANTICLICMATIC EVER. Burn in hell, NinjaKiwi. 1/5, played-only-for-badges.
Ow, my W key hurts. Also, the only game I've seen that has more bling-n-boom-n-whatsgoingon per pixel is Jets-n-Guns. Yay.
Also, protip for survival. Get at least to lvl36 to unlock rocket launcher (better to make it unlimited, but that's lvl40). Now spam up/w/click. You'll end off screen, and you can be damaged there only by UFOs. You'll only have to get down to get aid kit a few times. Tiring, but better than trying not to smash in those d--ned barriers.
Okay, so we've got human zombies, dog zombies, aand... werewolf zombies? So, there are normal, healthy, non-zombie-variety werewolves? No, bosses doesn't count, they're bosses.