One of our dogs loves to play fetch. The more the object he is fetching behaves like prey (a bouncing ball can change its trajectory in unexpected ways), the more our dog enjoys the game.
It would give him great pleasure to catch his next meal (food!). When we play fetch, he gets to experience that satisfaction (see, chase, catch) every 20 seconds where in real life it might be every 24 hours.
Take a rare moment that gives you pleasure. Find a way to simulate that rare moment of satisfaction. Play that simulation over and over again. You have the basis of a game.