Ah, game criticism and academic discussion is advancing pretty quick. It's good to see.
But I always feel like these discussions are a little hollow. Because games are basically a set of rules and content, most discussions revolve around one of these two concepts. We're seeing more talk about balance, about reward patterns, about graphic style rather than graphics... we even see some commentary about the psychological "value" and "art" of games such as Ico.
But 99% of the time, they're talking about the game. I don't really think that you should focus on the game, because the experience is what the game is actually about.
A game can have shitty gameplay and still be very good. A game can have shitty art and still be very good. A game can have shitty balance and still be very good. It can be on tight rails and be good. Hell, it can have no bad guys at all and still be very good. This is because what experiences games provide varies from game to game.
I'm not talking about categories of play, or the four different kinds of player, or whatever other academic nonsense somebody has come up with today. Categorizing these kinds of things is worse than useless, because it implies boundaries where there shouldn't be any.
But it is worth remembering that your game is not a collection of rules and art. It's an experience that many different kinds of people are going to live through.