I've always been a fan of long-running serialized fictions. Whether it was following the cast of the Hernandez Brothers' decades-spanning comic series, Love & Rockets as they aged in real time, or keeping up with the labyrinthine underworkings of Baltimore in The Wire, there's something that's always appealed to me about following characters for a long period. It gives them time to breathe and grow, more than would be possible in a single movie, book, or episode of a TV show.
It would stand to reason, then, that videogames, with their emphasis on sequels and long-running series (just look at Mega Man's 120+ sequels and spinoffs) would be the perfect vehicle for telling massive, several year spanning epics. Unfortunately, that's often not the case.
Many videogame sequels aren't really sequels at all, but rather games connected by motifs and mechanics. Supposedly there's some kind of chronology to Castlevania's 20+ titles, but you'd never know it. As long as we can plow through a castle slaughtering zombies, lycanthropes, and apparitions en route to Dracula, we're happy. We're not exactly the most demanding bunch when it comes to continuity in storytelling.
And there's good reason for that; videogames series are hard to keep track of. They take a long time to play, come out on different systems, and date themselves quickly. It's no wonder few rely on presumed knowledge as they don't want to alienate newcomers.
BioWare's Mass Effect series is ambitiously fighting the odds with its story-heavy trilogy that carries over all the player's choices between titles. If you want to catch up with the story so far before beginning Mass Effect 2, you'll have to go through hours of running from point A to point B shooting enemies, driving the Mako, and mucking about in your inventory. Granted, this is what makes it a game, but it also makes it a time sink as well.
If all you want is story, you could read a Mass Effect wiki to recap the plot in a matter of minutes. Though if you're a "learn by doing" person like me, or want to take advantage of its imported choices, you'll have to put in a 20+ hour investment playing it. To put that in perspective, one could watch the entirety of Party Down's two-season run in half that time and feel like they've spent much longer with its characters.
While combining plot and character development into gameplay is tricky, length can be changed and episodic gaming could prove more inviting for those catching up with a series. Committing to 20 hours can be intimidating, but chopping it up into several smaller chunks meant to be played separately is easier to swallow.