I can get over the cartoony art style, but I do not like the idea of levels for your home city ala Age of Empires 3. In that game, you earned better abilities to use as your city "leveled up" from experienced gained as you play. It seems they're taking this a step further and applying things like "equipment" for your cities/units/buildings that can increase their stats, to which I wonder where balance figures in all of this?
How is it fair that one guy (for example) has +20% damage bonus to his infantry while another guy (same "level") did not happen to pay for that stat boosting item with whatever currency the game uses (It's free to play, so I'm sure there will be "premium benefits")? RTS should always aim for perfect balance, injecting the RPG element into the game just seems like a bad move.