Strange isn't it? I don't like too big games
1. they're not easy to find your way around in.
2. It gets old before you reach the end (For me anyway. Took me a long time to complete Half life)
but then again, if it's too closed down, too on track you start feeling like you're being pushed along without a say in the matter. Much like the old interactive games which were basically movies where you clicked every now and then. Take Undying for an example. It's a darn large area you walk around in, but yet you feel it's one way, you might not see where to go, but you can't go other ways.
Then take something as old as Alone in the dark 1. You still had a bit of say as to where you were going. It had the freedom you needed while still giving you claustrophobia. What a work of art. (No drugs in AITD afaik)