Good concept, poor execution.
I simply feel that this game could have been something good. The upgrade system is down right disgusting. I find myself grinding on lower level cities for money to buy upgrades, which makes the game SEEM longer. I've made it to like level 8 or whatever and have 0 interest in continuing forward. The upgrades are far too expensive and give very little upgrade. It's like "ok buy the units first, grind money and buy the army size upgrade to max, then do whatever". That's my guide to this game. Very very very boring game once you actually start playing it. Furthermore I hate the fact that your units do not reset each wave. I had the giant turtle walk in with oh say, 25% hp or much less probably onto wave like 3(leading a group of 4, this was an earlier level). he had a healing priest and goblin tailing him. (The other goblin died that was in front of my turtle). I spam the spells but they become far too expensive to rely upon to "shut down" the defense towers. I find myself simply looking at another game that substitutes "grind playtime" for actual playtime. If it wasn't for the level of grinding you need to do, everyone would slam this game for being too short I'm sure. Sorry but you get an honest 4/10 and a 2/5.