I'm not much of a collector, or completionist. If I can see the ending of a game, I am set and would often put it on the shelf. Like Twilight Princess--I beat the final boss, watched the credits, and haven't touched it since (it's been over a month now). I don't have all the pieces of heart or all the Poe Souls or whatever. Perhaps if I only had that one game, I would do it.

If these sorts of things are done right, they shouldn't be a problem. I haven't finished Wind Waker precisely because of what was mentioned before.