Via Frank Patrick, Mihaly Csiksczentmihalyi on the componenets of enjoyment and flow:

Eight Components of Enjoyment

1. Confronting tasks that we have a chance of completing.

2. Concentration.

3. Concentration is possible because the task has clear goals.

4. Task provides immediate feedback.

5. A deep, effortless involvement removes from awareness the worries and frustrations of everyday life.

6. Enjoyable experiences allow one to exercise a sense of control over one’s actions.

7. Concern for self disappears, yet paradoxically the sense of self emerges stronger after the flow experience is over.

8. Sense of time is altered – hours pass by in minutes.