The term "classic" gets bandied about a lot, and is often applied to yet another annual update of some fat license or one more bog-standard FPS. "Beyond Good and Evil", though, is the real deal. The gameplay is quick and intuitive: some might even go so far as to call it "easy", but that, I feel, would be to miss the point. This is not a game where you have to be pixel-perfect to make that one crucial jump, or where you need to be an octopoidal stenographer to hammer in the killer combo. There are challenges, of skill and wit, but the game is never less than fair in either respect.
So what makes this a classic? The graphics are good, technically, but won't make your eyes pop. To some they might be "cartoony", others might call them "stylish". They are, though, beautifully designed. The characters, vehicles, buildings and landscapes all hang together: they all belong. And not just in their physical design: there's a real sense of personality about this game. It's not just a bunch of generic fluff that could be grafted into any game, anywhere; these characters, these locations, stories and events belong to this game and this game only. It wouldn't work anywhere else.
This is what makes it a true classic. You are -- quickly and painlessly -- drawn into the gameworld. You start believing in it, and start caring about it, in a way that very few other games can match. This is no numb, dumb button-bashing timewaster: it's a genuine, absorbing pleasure to play.