Very pretty game. The poor dying chicken sounds were amusing. The spreading fire between objects was cool.
I felt the hammer animation wasn't strong enough. It feels like someone slightly holding back their strike to deal less damage.
Waiting for the cooldown on my attack is boring, especially when there's nothing else to do. I suggest giving the player an instantly repeatable attack in addition to a cooldown attack so the player always has access to some attack. Maybe when you unlock a new cooldown attack, the previous cooldown attack becomes the player's rapid attack, triggered by the right mouse button.
It seems like sometimes there are invisible chickens. I hear them, but don't see them anywhere on the level.