The game is fun, but still has a lot of bugs:
Knights and archers sometimes freeze when you play (or fight?) a lot. While the knights will be useless, the archers will still shoot, even though they won't move on their own. Refreshing the site will unfreeze them.
Sometimes, the opponent's archers fly up high in the sky.
Miners sometimes walk through the ground. They also tend to get stuck sometimes, especially when there isn't much ore left. The site has to be refreshed or the castle has to be moved to unstuck the miners.
Holding left control while right clicking to bypass the sell check doesn't work, the sell check will pop up on every right click regardless.
MMR resets to 600 when you refresh the site. You keep the leaderboard entry if you don't fight, but once you do, the leaderboard updates to adjust the player's place with 600 MMR. That's kinda sad if you grind your way up to 1000+ MMR and then after a site refresh can't fight anymore without losing a lot.
I lost a good chunk of my castle once. I think I fought an enemy and accidentally refreshed the site while doing that, so my damaged castle was saved instead of my proper castle.
In my opinion, dirt and wood blocks should have somewhat higher hitpoints than their original resource counterparts. The way it's designed now makes dirt blocks useless.
The pathfinding of the miners could be improved a bit. It's especially frustrating if the miners walk a long way to a spot where no ore is left, because they chose to walk this path when there was still some ore left but it got mined away while they were walking.