OMG
I WAS ABSOLUTELY loving this game UNTIL the last level. I spent over an hour building an army of 300 (let me repeat, 300!) totem units... ONLY TO FIND OUT that the motherf*cking boss absorbs magic damage. AND NOT ONLY THAT, I healed him to over 150% of his starting life before I noticed.
The constructive part of this comment? DON'T MAKE IT SO THAT UNITS BECOME USELESS AGAINST THE LAST BOSS. Oh, and like everyone else said before, re-upgrading every level was a dumb idea.
Ok, not that that's out of my system: great game, super addicting.