Just get 8, 9 upgrades in Tower Upgrade Section and you're a winner with a Level 5 Super Tower. Ah common, I've seen game that with no strategie needed, but this one...
After a getting a 15-15-15-15-15 virus upgrade, and other upgrades (except bombs), game gets easy and laggy. Lost abou $15000 in a city just cause' my zombies killed everyone and I didn't found a found to catch (quickly) all crystal and money badgs.
I was a Berseker fan. But some games came and huh... they weren't good. For me, this game "cleans" my vision of Berseker Crew. This game is very good. 4/5.