As time passes, that frisky little kitten that used to scamper all around the house will start to settle down. As more years go by, playtime will decrease as naptime increases. There's nothing wrong with your cat; it's just getting older. Most cats live about 15 years. Some grow to be 20 or older. Like people, cats need more care in their golden years. Make sure your cat get regular checkups from your vet, who knows which diseases and conditions are more likely to occur in an older cat. You may also need to change your cat's diet to one that's designed for the nutritional needs of an older animal. Finally, even though your cat may not want to play as much as when it was younger, it still needs some exercise. Play with it. You'll both enjoy the interaction.