Hitting him as many times as possible should do the trick!
Edit: Okay, I eventually got him! It was just hard!
Now on to get 100%. Thanks!
I love the atmosphere of the game so much. It's cosy and comforting even when frustrating :)
Edit2: Steam says there is partial controller support but in the game I can't change the controller setting from 'keyboard' is that how it's supposed to be?