Depends on the genre as well. An action adventure like Uncharted could've lasted 41 hours and I would've still enjoyed it, although I know it's hard to keep that pace going for insane amounts of time.
An RPG that ends after 10 hours is laughable though.
Shooters are the genre that need longer single players though,because they often just tack on a singleplayer for the heck of it.







