Depends on the game, I think. I've clocked up many hundreds of hours in Skyrim and, to a lesser extent, Oblivion, and both games continue offering something new to see, try or explore. The vastness of the game world is part of the appeal, and it rewards the time invested in it.

Sometimes, though, a shorter journey can be equally rewarding, only in a different way. The Last of Us is a good example. It takes handful of hours to complete, at most, but the journey is so engaging, yet draining and harrowing that dragging it on longer would be borderline torturous.

A lot of it comes down replayability. Even a 'short' game can turn into something a lot longer if you keep coming back to it again. If each playthrough only takes a few hours, you might simply not notice when your total playtime is into the dozens, or even hundreds of hours. I'm looking at you, Tekken and Metal Gear Solid series, among others.