Just thinking out loud...
Work contributes to the needs of people. Play is for enjoyment and for rest from work. Today is my first day of part-time work-for-myself. Working three days a week (after working hard to get my finances well enough in order), I now have about 18 extra hours of free time each week. I have always planned to use that time to work, specifically to build a digital product. However as I decide what to build, my work can become play if it builds a product that contributes only to play. An XBox game, for example. But what if that "play" makes money, helping provide for my own and my family's needs? I have two thoughts on that. One, if it is going to make money then I think it is both play and work. However, to make enough money from it to be considered practical income, would require a lot of work, typically more so than creating something that meets others' needs. (Because, to repeat what has been said before, people are willing to pay for what they need more than for enjoyment, and an entertainment product competes with all other entertainment products, because they all provide basically the same thing.) So for all practical purposes, building something for play should be considered play. If you want income, do work; it'll be a lot less work than play will be.
On the other hand, why have I worked hard to be able to go part-time? Because I wanted to do the work that I enjoy most, which could be said as, I wanted to, in a sense, play for work. Sounds pretty vain put that way. But there is I think a valid, correct perspective to have regarding work that is also play. As the famous saying goes, "Find something you love to do and you’ll never have to work a day in your life." Each of us has a type, or several types, of work that we are passionate about. There is nothing wrong with enjoying your work! And in fact, the world benefits more when we choose a work that we enjoy, because it is that work in which we will be most effective.