The main story of Rage is about 5 hours (if you skip the needless dialogue). Skipping the side missions and sewers is 2/3's of the game. Not sure how that was relevant.
As for the length of the game, @31 hours you must be really bored or really like the racing and gambling. Even screwing around it only took me 13.5 hours with all side missions except the delivery ones, and I beat everyone at cards, gambling, and finished about 30% of the racing (all that was needed). This is a FPS after all, not a half-baked 3P vehicle combat game (even the AI cannot avoid the invisible walls). Conversely, you must skip quite a bit for the game to take less than 10 hours (or use the trainer). There are too many cut-scenes, time delayed missions, racing, and other tactics that prevent a mere speed run (unless it is on Easy and then you should just keep walking, as Easy player do not count - doubly in this easy game).
The game does not need to be 30+ hours long, but if it is this short it should have re-playability. Since we have seen every level twice (since they recycle), and there are no possible deviations in what little story there is (as we have no choice), DLC or mods are the only hope for me to play this again in the next 9 months (or so). That is where the design of Rage fails to live up to a modern day FPS.
So, to the OP's question - The length is not as important as the game design and quality. Since the first map was weak, and the second map was shorter, the game finished at around the right time. If it had less filler and more FPS (or any RPG elements - ammo and crafting are not RPG elements) it would be a great length since customization would allow for some re-playability. I am glad it ended were it did, as it was not getting any better. It had maxed out with the Gearheads (best AI in the game). I found it funny how they were tougher than the Authority...
I was never asking that question for me. I just thought as if someone else was asking it. I'll say it, I think Rage is perfect, have yet to experience this horrid ending everyone is so mad about but so far it's exactly what I expected and more. I say that because I was not expecting the racing to be good and now I love it. People are complaining that the game is way too short but then they are saying try don't want to do the extra things. To me that sounds like an oxy moron, sorry. If your playing the game then play everything the game has to offer. It's there because it's part of the game. It's not just there to skip. The developers wanted us to enjoy ourselves and that what I did and will continue to do.
Also you said that I must of done a whole lot of gambling and other stuff to make it @30 hours and I'm still not done. Sure I did. Only because once again it's part of the game, why wouldn't I. Actually I take my time in levels and search for items and use a variety of weapons, that takes time.
It's basically like someone who complains dinner did not fill them up but they skipped the appetizer and desert, why skip it it's always the best part for me. It's fun to see what the developers come up with for mini games and side quests. It's where they really get to put in their ideas and get as crazy as they want.
I'm not trying to be rude to you, I see you on here all the time and know you like the game. I'm just so sick of hearing all the bad things about Rage. Compared to almost every game that comes out Rage is a masterpiece.want short or game that has a bad saving method try homefront or dead island(I like dead island).