There is no single right length for playtime. Some cats are ready to chase right away, while others prefer to watch for a moment before joining in. Look for the signals that your cat is interested: focused attention, a low stalk, ears pointed toward the toy, or a sudden burst of movement. When those signals fade, it is fine to call it a day.
It helps to give the game a beginning, middle, and end. Start slowly so your cat can spot the toy. Build up to a few short chases. Then make room for a final pounce or catch before you put the toy away. That small finish can make a session feel complete instead of ending abruptly while your cat is still searching for where the toy went.
Keep play comfortable and supervised. Check teaser toys for loose parts before use, choose a clear area when a cat is moving quickly, and put away anything that is not meant to be chewed or left out. A short, attentive session is more valuable than leaving a toy running long after your cat has lost interest.
Do not worry about making every session elaborate. A few minutes before breakfast, a quick afternoon break, or a calmer evening game can all be enough to give your cat something engaging to do. Consistency is more useful than trying to create a big play event once in a while. Keep a toy within easy reach, then let your cat's mood decide whether today calls for a gentle watch, a quick chase, or a full pounce.