This post was originally written (by me) on March 20, 2008. The original is no longer available.
When you read a review for a game, or even just talk to someone about a game, the concept of replay value seems to crop up frequently. Normally this refers to choices made over the course of the game (as in Kotor or any other Bioware game) which can be made differently in subsequent plays through. Or it may refer to the various so-called emergent gameplay elements found in open world games like GTA. In either case it boils down to the same thing: play this game again and it will be different. I play through quite a few games, from the really short Max Payne 2 through to ridiculously long games like Final Fantasy X, and it has never occurred to me to play through a 50 hour roleplaying game again because I didn't see what happened in the alternate quests if I played evil. As with many of the systemic problems with modern games, I think the root cause of the idea that a game should be long or change on subsequent play throughs is caused by the fact that games are expensive. I don't hold to the same philosophy, but the majority of gamers seem to be of the opinion that if a game costs four or five times as much as a movie, then they should get ten or fifteen times as much entertainment out of the product. This is probably somewhat dependent on an individual's dispoable income. If somebody only has enough money to buy three or four games a year, then they will still expect the same hours of entertainment as somebody who can affor to buy a dozen or more, at which point the quantity of a game becomes at least as important as its quality.
That tangent on relative entertainment economics aside, back to my original point. The shorter games I tend to play through multiple times because most of the enjoyment I get is in the short term gameplay elements. Diving around shooting guys in slow motion in Max Payne is fun, really fun, and if I get bored after a few hours I can stop playing because I've already finished it before. Any game that lasts over 20 hours is going to contain a lot of slog, like the non-stop random encounters of a JRPG or the cross city transit in a GTA, which I'm content to play through once, but if I want to just see the alternate ending, I really don't want to play two hundred uninteresting random fights first.
I guess what I'm saying is that people rewatch movies and TV shows and they re-read books, and with the exception of choose your own adventure books, these never change. People don't reconsume media in the hope of a different experience, they do it because they want to relive the good experience of the first consumption. I would rather see a developer put all of their effort into 10 hours of brilliant game than 50 hours of pretty good game or 200 hours of mediocre game. If it's good enough, I'll play through it again because it's good, not because I wasn't allowed to see it all the first time through.