Some helpful suggestions from Perfect Paws:
"If he begins to bite or scratch you, immediately scream "OUCH," stop the play session, walk away and ignore him. Curtailing a play session is an extremely potent punishment. Your cat will soon learn that it is his own rough behavior that causes the abrupt end of an enjoyable play session.
If your cat attacks you in play, entice him to attack when your are prepared with a plant sprayer. A few repetitions of an attack-squirt sequence should convince him to attack his toys instead of you. "
BTW, the squirt bottle works WONDERS! We recently had to cat-sit an adult cat that had been allowed to walk on counters, sinks and tables by his real owner. We did not want that to happen at our house! It took only 1 spray from the bottle at each location, along with a firmly shouted "NO!", to break the cat of this habit! And, yes, it still loves us and comes for petting, etc. Cats need discipline, too, along with love.