Seriously, the 80th floor is the last unless you pay? I would understand if it were the same floors as EC1 but with 20 more if you pay, but this? This is unacceptable. That is not content worth paying for, that's content that should have been the full game, you lazy, moneygrubbing polesmoker. Go shove a pineapple up your ass, please. This business model needs to die.
The game tells me my browser doesn't support HTML5. I'm pretty sure it does, since I develop HTML5 games and test them in this browser. You may want to look into that.
You should change it so that units attacking the castle stop to fight new units spawned by that castle instead of letting themselves get wiped out. Other than that, pretty neat game!
The feature I need is localStorage. If it doesn't work, it shows that error :(