On MMORPG.com's games list, you can find a couple games who don't usually identify as games. If you go among a group of SL "residents" and ask if they are playing a game, most of them will tell you "Second Life isn't a game."
So what is it that makes a "virtual world" different from a "game" MMO?
Argument 1: user created content -- refutation, Eve Online. If space is about the only thing in Eve that's there before we log in, and land is about the only thing in SL, this isn't it.
Argument 2: victory conditions are not defined by the game programmer -- Eve again -- you can get rich, you can explore, you can hang out and dis each other. Seems like about the same things either place. Admittedly, the sex animations are better in SL, but the costumes and "dancing" are pretty sleek in Eve too.
Is Second Life less of a game, or is it just a collection of games -- roleplaying games (which most admitted games do rather poorly in multiplayer mode), financial games, social games, fashion games, dating games, dance games, collaborative games, serious games and silly games.
Personally, I'd tend to say my first life is a game. I'm an entrepreneur. I've been active in politics, and in policy changing nonprofits.
Is LinkedIn (a business networking site) a game if you are trying to increase either the reach or the quality of your connections -- or trying for that ideal of increasing both?
So, I believe, if we look at how people think about these games, how people use them, and how they conjoin people, or help people play with identity, or help them learn, waste time, refresh themselves, take out frustrations -- where are the real differences?