Play, of course, can mean different things to different people. Racing or working out may be play for some, while artistic projects may be for others. Sometimes play is recreation, sometimes stillness, and sometimes creativity. The key is that playfulness is its own reward; the goal is not results but enjoyment.
I've always been a fairly solitary person, but what defines play for me depends on my mood. Sometimes it's having fun with friends at the local medieval fair, and sometimes it's spending hours reading a wonderful book with a cup of tea. Although I can't relate to those for whom play is very competitive or action-driven, I can understand how these activities would appeal to people.
Regardless of what play looks like for you, make sure you actually DO it! All work and no play doesn't just make Jack a dull boy, it leads to all sorts of stress-related dis-ease and emotional disturbance! We are human BE-ings, and enjoyment of that BE-ing is key to a healthy, holistic lifestyle.