Another comment and stuff, there should be 5 max upgarades, witch you could deside between population growing, max population on that keep, atack/defense and each upgarade counts as 1/5 of the total upgarades you can do. As an example, growning normally is 10 (an example) then grown it to 11 if leveled up, then 12... etc... same with the other upgarades. Note: for defensive/offensive there should be a full offensive, full defensive and hybrid creeps upgarades.
too easy game, just take the neutral villages near of you, then upgarade the not in danger ones, and then, just click from the far castle to these frontier enemies castles... I had no really serius problems at playing this, it needs a way of more rules and probably a better AI.
Is it intentional that if 2 poison towers or more hit the same target for some reasson, the poisoning damage per second is the adition of both towers poisoning powers? I noticed that if 2 poison towers hit the same target at the same time the damage output is absurdly high for too low price.
Another point, poison towers are Overpowered in levels 11-15 because by ONLY buying 1 and upgarind it, I cleared leveles 11, 12, 13 and 14 by doing a poisoning tower and upgarading it to levels 3, 4 and 5 (max)
 "mini Tower Defence (mTD)"){kind=icon}
 "Castles Wars"){kind=icon}