Just purchased the game and put about 20 hours into it. As it stands I have recommended to my gaming group to not purchase the game. It has the potential to be fun and have huge replay value but here are my initial thoughts.
Economy is horrid. There is almost no value to upgrading hovels. Either make the lumber yards upgradeable so the upkeep cost of wood is manageable or remove the wood upkeep. Some other reworks need to be looked at to balance the economy to add the fun factor.
Slow down the waves. As it stands you have little or no time to explore. by the time your slow units get outside your area and start exploring the next wave is on it’s way. Maybe a scaleable wave timer that is much slower early on and gets faster late in game.
perks/feats/upgraded hero. Allow some aspect of your hero to carry over from game to game? I understand this may unbalance them but small things like a speed increase, attack speed, DMG. Almost and RPG aspect. (1% increase to speed per point spent and you earn a couple points per level)
I’ve seen a few comment about fire but I don’t mind it too much. Except with stone walls. Fire should have little lasting impact on stone walls, just doesn’t make much sense.
That’s my initial thoughts. Biggest concern is the economy… it’s no fun to spend hours building your base to have your economy go in the tank after one lucky wave.