X-10 Very short
10-20 Short
20-30 Medium
30-40 Long
40-X Very long
The expectation depends on the game though. Ever since the incorporation of voice acting, elmination of CGI, cinematic camera work, etc. story has become shorter do to costs. I wouldn't expect an Uncharted game to go on for 40 hours because that would be really expensive to make and to be honest what would the story be about? The gameplay isn't that time consuming in that game either. A final fantasy, I expect a longer story but gameplay takes up a big chunk of those games, but then you have to incorporate side quests and stuff. A game shouldn't be so long that it is unbearable either. Didn't Xenosaga have over 20 hours of cuts scenes alone? And that game dragged on. Anything that takes more than 60 to 80 hours has to start askings itself what it is doing or it might be too late.
Before the PS3 everyone was nice to me :(
