Can A Game World Be Too Big?

Title says it all...

I've been making steady progress on generating procedural content for a retro 2d/3d space game recently. So far I've got random tile planets, psuedo-3D solar systems and a freaking huge map of visitable stars. But as I've toyed with going farther along the macro (sectors to galaxy) and micro (towns to floor plans) I've been plagued by whether or not it's possible to have too much of a good thing.

I've posted about this before (back when it was more of an "on the drawing board" thing) but now that I can play things a bit the problem is far less abstract. It's got me thinking about whether or not there is really any overall game goal that can justify so much territory. If a game world is too large, there's a chance that anything you do in it will either take forever (by din of total real estate) or be dwarfed by the sheer size of space in comparison to what you can do in it. Even if the ultimate goal is exploration in sandbox gameplay it seems to me that the size / depth creates a kind of tension that's opposed to the satisfaction / reward of completing the game.

While this is certainly a problem with physical space, it seems to me that it can be a problem with space of any kind, especially possibility space. A game that offers zillions of weapons and armors, things to collect or tasks to complete probably suffers from the same potential problem.

So what do you think? Is it possible for the size of a world (literally or figuratively) to dwarf and thereby invalidate the player? If so, how big is too big? If not, why not?