Cool concept! I had a little bit of an issue where the knight killed my skeleton OUTSIDE the green space and the game just basically lost and I had to restart. It should probably restart automatically or say you lost if this is intentional.
The knight can kill your skeleton if he gets too close, if the knight isn't in the green zone and your skeletons are dead, you can just press R to restart the room. It will only automatically restart if the knight dies.