[KVFinn]

There's a third category that I would put most of the games I enjoy into:

-Long and Deep: Games you can play for huge amounts of time but don't depend on an artificial sense of progress to do it. Strategy games, roguelikes, competitive games, etc. Games where you level up yourself by getting better, instead of the character in the game.

[jjjeffrey]

That's a great point. I play Nethack now and then, and I like how I can play it for an evening and then walk away, satisfied that I'll never beat it.