It's not that bad, actually. The full game is a lot better than the demo and the story is interesting enough to follow through to the end. I beat the game once already and they do give you an extra mode to play once you beat the game, where you get this real nice high speed boost pack. In a way, it's no worse than any Resident Evil game, and actually has a couple of gimmicks that make it less tired than Resident Evil. I've played the RE and DC games till the cows come home, so I picked this one up more so to add to that collection.
Actually, the best part of the game is the control. It's very tight and travelling around with the boost pack is very nice and comfortable. In a way, it's part of what keeps the game from slowing down on you. The combos are sort of taken from the Dino Crisis 2 side of things, and is your main way of getting money to buy stuff. Thus it is more profitable to find rooms with many creatures than the few if you want to build money fast. You'll need it too, as you want to be nearly maxed out by the time you get to the end of the game. The way points exponentially increase with each new monster you add to the combo (up to 8) and then keep up that high scoring points for each afterwards, gives you a lot of incentive to rush down those easier beasts. Good that you have a jet pack to help reach them before the counter dissappears (ending the combo), you'll need it sometimes. My highest combo is 25, which I've accomplished multiple times.
Length is more or less typical of the longer playing survival horrors (the first time through). It should take you around 10-12 playing hours if you are typically good or well practiced at these games. The RPG-like building up parts are part of what gives the game its length. There are a few issues with the camera and such, but if there is something one shouldn't complain about is control. The control is better than any Capcom survival horror that came before it. Actually, the demo had the most glaring parts of the camera. However, you never need to precisely aim your shots or anything as it has an auto aim function and the surround sound solves a lot of issues with camera switching. But the game flows smoothly and keeps things continuous (motion and position-wise), and once you get that into your head, you'll be sweeping along and strafing down beasts, jumping and dodging, in no time.
Another major aspect of the game, that isn't in the demo, is the transforming ship idea. A nice gimmick that is put to good use. Every major section of the ship is a transformer(TM). There are kiosks for each part of the ship (not all immediately working the first time you see them) that shape shift the section to a different configuration and positions, all of them affecting gameplay and altering your environment. Rooms will get shifted sideways, other rooms will get smashed together with other rooms, and perhaps some hidden locations will get revealed. Certain doors open as they work only in certain configurations, etc.
Even with all of this added (certainly giving the player a bit more than the past games in either Res evil or Dino Crisis lore), the game loses a bit of wow factor to those who played those games to death. Partially because you start to get that (just another survival horror) perspective after a while. And you become a bit jaded against any of them unless they take on a very different view. This is about as much as Capcom has strayed from the original formula, but take in consideration that they only stray but so far from the original formula for all their games. I'd say this one was pretty good as it takes a lot to keep me interested in a survival horror action game, of this manner, these days. If you liked the earlier DC games, you'll probably get a kick out of this one. It's Burning Rangers meets Dino Crisis, in a few ways (a little closer to DC2, as it is more challenging high action than "jump at you" scares. Though it does seem a bit more up in story presentation than 2.). The no-grav locales also mix things up a bit, as well. However, like pretty much any Capcom survival horror game, I'd would say rent it first, and you'll probably get more of your moneys worth if you get it cheaper than the initial asking price. It's still not something as wickedly different as Fatal Frame.