I thought I wouldn't like it but I did :P It only gets 3/5 because I don't think barricade should be a "weapon"...it should have it's own button...I'm tired of running out of minigun ammo in a mob of zombies and having it switch to barricade >.<
You don't have to play the levels through twice. What you *should* do is use initial upgrades for prestige bonus from kills, damage and accuracy...if you start with those three upgrades you never have to replay levels.
Yes, lightning towers can be great, once they level up...during the end of the lightning campaign when I had a full row of level 5 lightning towers, I kicked serious ass...
3/5. It could've been a much better game if the designer had added different attack types for the balloons (fire bomb? kamikaze? missiles?) and taken a few of the levels out of the middle-game.
The lightning and oil campaigns are easy. Oh, and it looks like you can skip some of the levels, so it's not as long as y'all are complaining that it is...