I believe that the game should be based on a "minimum hours to finish the game" calculated from the "Retail price in dollars = MINIMUM Hours needed to finish the game." Games that are short make the player (buyer) feel ripped off and like movies, games that are too long are usually less fun and less entertaining. In my Gamasutra article "The Pedersen Principles," I suggest this equation (The Yardstick) and use the acronym KISS (Keep It Simple, Stupid) to provide entertaining, intuitive gameplay.
Roger E Pedersen, PSI Software
I don't think that there is an actual hour-to-$ ratio that can truly be quantified. I think that it depends more on the actual game and how well it's crafted. I don't mind paying $70 for something that is truly engaging the entire time I'm playing it, whether it be 20 hours or 1000+ hours. Two games that were considered short that people didn't mind (that spring to my mind) are God of War and Chronicles of Riddick. Both were worth the price, but many felt they were too short. I have heard it said that if someone plays a game that they think is too short, then that means that they want more.
I would rather have a shorter game that was tight and polished than one that is 1000+ hours of bugs and crashes. One way we can help/compromise this may be with episodic content. Release the main game for a lower price, then have regular updates with new content for a lower price. It may work, but it suffers from the possible problem of charging way too much and having the same lack of polish a lot of games suffer. It all comes down to making and polishing your game to the Nth degree.
Liam Hislop, Full Sail
Game length is obviously very important. I still spend a fair amount of time playing a wide variety of games, even now that I'm much busier. That said, I'll be honest when I say I RARELY even finish games. The last few games I can remember finishing in the past 2-3 years were maybe Half-Life 2, its Episode 1 content, and Sid Meier's Pirates!. Games that are 6-10 hours have a very important place along with the 60-100 hour experiences. I'm more likely to finish HL2: Episode 1-style games where the content is engaging for 2-3 hours. I get a kick out of the huge, expansive titles like Oblivion or San Andreas, but there's not a chance I'm going to finish it. Games often drag out and once the novelty of the mechanics is gone, it's usually just variations of things you've already seen.
I don't think the length of the game is as important as the experience. If a tight, well produced and truly fun game only takes 6 hours to play, so be it. That seems to be acceptable to many people and like the 90 minute popcorn-fest summer film, that's what it takes to succeed, right? The acceptance of the market?
This industry needs to get over these over-simplifications. The film industry doesn't get in a public debate over the difference between a 3 hour epic and a 90 minute comedy. Tickets to both films cost the same. The bottom line is that consumers vote with their wallets. We should continue to monitor what folks buy and what they don't. As a gamer myself, I prefer the shorter experiences as I simply do not have time to play 40 hour games all the way through. At some point the cost to value ratio diminishes and I decide not to play at all.
A good example is comic books. Years ago they were less than a dollar for approximately twenty pages. Depending on the creative team involved a comic could be read in somewhere between 5 and 25 minutes. Fast forward to today when most comics still match in page count/reading time but cost around $3. I bailed a few years ago when the price jumped over $2. The cost was greater than what I was willing to spend for that entertainment. $70 feels like too much, but then again I really, really love Gears of War.