I'd say it depends on the player, and you can't please them all!

There are those that want to be able to complete a game and brag amongst their friends saying they completed it in 6 hours, then there are those who buy a game and keep playing it for months, it's usually stating "complete freedom" on the box that will determine whether a player will buy it.

I think saying it's the terrain that kills a game is somewhat of a cliche that comes with outdoor environments. Whether you get huge environment packed with activity and non-stop adventure, a slower paced game designed for capturing emotion, or an empty field, a designer should be able to take each of these and make it work for the audience they're trying to target.

Terrains don't kill games, the inability to create playable environments that does.

(and btw FoxZero you fast travel without a horse )