Playing with your cat is the best possible way to build up a bond between the two of you. She will become more attached and you will feel closer to her.
The best way to ensure that your cat does not become overweight is by feeding him correctly with a balanced diet, but exercise also plays a part in keeping your kitty healthy. If yours is an indoor cat, then playing with you may be his only opportunity for exertion and staying trim.
Playing will help your cat to become confident. Also regular play periods, coupled with petting sessions, will get your cat used to human interaction, he will be less likely to shy away and hide, when visitors call.
Playing will help your cat develop his hunting abilities. Hunting is a natural instinct for all cats, a cat confined to indoors usually has little chance to express and develop this instinct. Encourage kitty to chase a toy mouse, allow him to pounce for the 'kill'. This will aid him should he ever get lost and need to find food.
Playing will help your cat release aggression. Cats often display aggressive traits through boredom. Tutor your cat not to scratch, bite or attack you with play sessions. Use praise to reward your cat for playing gently, as soon as he shows any sign he is about to use his teeth or claws - end the play session. This will teach your cat that aggressive cat behavior is best directed to his toys, and not you!
Cats need fun in their lives, just like humans need it. Relieve the monotony of eating, snoozing and using the litter box by putting a bit of fun in your cats life. You will have a happier, more confident and less aggressive kitty.