>This is a good question as the answer should be self-evident -- i.e. they were just great, well-written fun games -- but it's not. As pure gaming, they weren't "great" in the classical sense. I mean, after you've finished them, you can't keep playing them over and over because there's nothing really to "play."

And who said games should be player multiple times?

One can conceive of one-time games, and adventure games were precisely that.