Improved meat bouncing, sounds play in rhythm

Changed mechanics a bit with panels so that meat bouncing works a bit
better; changed the physics slightly so that gravity -> velocity
interaction is better, made sounds work if you hit ball with panel at
proper time. still need to make it so that ball splatters rather than
continues bouncing if you fail.
Also made it such that you can press q during gameplay state to view
current frame rate. useful!