Better hitting and other tweaks

It feels a bit cumbersome hitting the puck with the player. It would probably be easier if you make the player smaller. Try using a setRadius call in its constructor to make it smaller. In doing this you reduce the mass of the player (normally equal to the density times the radius cubed), so to keep this up, increase the density as well, using a setDensity call.

It would be nice have a sound effect when you hit the ball. You can do this by overriding the player's collide method similar to the way in which we override it in the Gamestub code, though here all we want to do is make a noise when colliding with the puck and not change health or score in the collide.

It might be better to have the game world a little bigger.

Make sure you have the maximum speeds and the frictions tweaked to good values.