Enjoyment is not addictive because enjoyment is intimately connected with creativity. People play a video game until it no longer provides a mechanism for them to exert their creativity on. There are some games like chess that are so deep that nobody ever reaches the bottom. If there were a bottom, then chess grandmasters would instantly lose interest in chess as soon as they reached it. It's funny that nowadays chess has in our society increased its status in proportion to the prize money that the best chess players win.