Oh yes, the Bounty Hunter is really cool. Theres other things I want to tell you about him, but I don't want to give anything away or ruin the surprise.
As for the length, it's hard to say but I must have been playing for a couple of hours by now, and I haven't got any achievements whatsoever yet. I know that I haven't even gotten to the Tower or Pit challenges yet, so it seems like it's fairly long. It also has co-op challenges and single player timed challenges I think.
As for the Dreamcasty feel, I dont' know if I would say Dreamcast specifically, but it does have a very distinct feel about it. Some of the level designs feel very reminiscent of Dreamcast games, and I think coupled with the older looking graphics (since it's pretty much an independant game) might give it that old-fashioned feeling. I think it was Barry who pointed out that the world seems a bit like Panzer Dragoon's universe, so that could have something to do with it as well.