Play time is a terrible measure for cost of creating a game. Yes, maybe the average playtime of old NES games was shorter, but the amount of artists involved was minimal and they didn't do it by having more content, they did it by stealing coin-sucking GAME OVERs from arcades.
I care about quality play time over just about any other metric. How long is a game actually enjoyable - maximizing that seems like it should be the clear goal, no?
