The argument of “value doesn’t depend on time” only holds when neglecting the recreational aspect of gaming. After an intense time of highly involved brain-work playing “Tetris” for some ten minutes can feel quite balancing to my cerebral functions. Many games can extend these relaxation periods to hours. I doubt though that the brain – or since the Wii even the body – would require that much re-balancing. Or that there is novel experience aplenty in those games. There is a point where continuous gaming gets the smell of addiction. I realize I passed this point when I wake up from gaming feeling sorry for the waste of time.
Time matters for movies, as the attention span of average consumers is limited to about 2 hours. The attention span of consumers of video games in the past seems to have been considerably longer, but today’s crowd of casual gamers tells us that byte-sized game content might simply be better digestible for everybody. If anything, this “fashion” extends the medium with new expressive tools, the same way that a TV-show narrative profits from segmentation when developing characters over longer periods of time. I am not saying we should all start selling our games in episodes, but we could take advantage of these tools to convey whats on our mind to a wider audience; an FPS-mini game inside a 2D-browser game comes to mind ;). The key point here is that if we fret over the way the “new Core user” wants to play we should not devalue the experiences we want to convey by thinking about how much time we can make players spend with making them, The mere fact that in games “XP” is a numerical value hints towards an absence of actual experience.
If the “Experience/Time”-ratio were the actual value of a game, we would pay $50 for games like Braid, or even for Angry Birds, and $0.99 for “Avatar”. A serious high-value game IMHO is self-conscious and takes no more time than neccessary to convey it’s experience gracefully. Sometimes even a Haiku is enough.