I'm finding Chien's last couple posts in this thread to be hilarious, and its hard to explain why, lol.
Anyway, I agree with joxer, 25 hours seems skimpy for a rpg of this kind.
And its not just about number of hours either. It very much depends on the genre of the game. An old school rpg is expected to be a lengthy game, like say, 50-100 hours, or even more. That is simply tradition.
In contrast, a traditional pure first person shooter released today would be unthinkable as a 25 hour game, at least when looking at most of the big titles put out by the big name developers. These type games have seemed to get shorter and shorter. Most of those games are as little as 5 hours (or less) to around 10 hours or so, maybe a little longer on occasion. I'm speaking of the single player main campaign only here, and not multiplayer.
Then we can consider the open world shooter games with rpg elements such as Far Cry 3 and Dead Island, once again, a different kettle of fish. Those games have much more game time than the traditional FPS, and to them 25 hours is much more of a "normal" or expected amount of game play.
Anyway, I'm rambling, but the point is what players expect in terms of game hours very much is determined by the game genre, and can have wide variations because of that. Its not so simple, in other words.