I tell you all, if i see one more comment about "The game is stupid, because premium 1/5" i am going to get out of here. You're stupid, because the developer could make all the game premium, and you even are complaining about some settings, without them you even got a very big game to complete.
The game is great, but i think that units should be adjusted for free, but you can upgrade them with money, to give them additional bonuses such as: 30% more damage. Just a suggestion through. And lives are stupid, because Nerdook's games have a great replayable value.