My KOTOR games were all well under 30 hours, some even under 20 and I did almost everything. You're insane, winslow. :)
My point wasn't that I like short games (I don't necessarily -- I think 20-30 hours is the perfect game length), but that it's kind of unique. It does feel short, but the replay value is so high (there's so many "holy shit" moments that you want to see again) that it's worth playing through again. It takes me back to the days of having a friend over on a day after school and BEATING, not just playing, River City Ransom. I'm not saying that I wouldn't rather it be a longer game, but in this case, it works. A game nobody has ever heard of called 'Psi-Ops: The Mindgate Conspiracy' is awesome and it's the same way. You can beat it with two days of a couple of hours apiece and I've probably beaten it 4 times since I've gotten it. Same with the PS2 Prince of Persias (love 'em). Sometimes, it's nice to not have to be engaged in a game like an RPG. You play it for a few days, beat it, and it was a nice little tight package, instead of being a huge game that you really have to think about.
Plus, in GoW, the hard modes probably take at least 15 hours to beat, I'd guess, because the enemies are tougher and take more hits. You have to be smarter than just mashing buttons, so there you go, replay. It's like beating ANY Capcom game for the SNES and being told "Please try on a harder level!" :) I'd prefer it as a 20 hour game, but it works in this case.. Metal Gear Solid 3 probably wouldn't, on the flip side, and I like that even better. Does that make sense, bro?