Bash Zombies with a hammer.
Quick Hit: Quickly click, drag and release the mouse to swing the hammer.
Power Hit: Click and drag the mouse but do not release the mouse. Your hits will do more damage the faster and farther you drag the mouse.
Block: Double click to block. If you hold down the mouse after you block you can move the hammer back and forth and continue blocking.
Endurance: Every time you swing the hammer your endurance goes down a bit. When your endurance is low your attacks will be weaker. If your endurance is in the red zone you will be unable to attack. You gain endurance over time or if you block an attack.