In fact, people tend to be happiest when they’re working hard. That’s why games are so popular and so many people spend so much time playing them. Games provide achievable goals with rules and obstacles. Games make you work hard, but that means you’re having fun!
If you’re interested in learning more, I highly recommend checking out Jane McGonigal’s book Reality is Broken. I’ve just started the book but have already learned a lot about the psychology and real world application of games.