I think in the end, this game might play as Destroy all humans, unless there isn't much more to do than capturing ghosts.
Another problem would be if there were more to do than capturing ghosts, what would that be?
All they did was go to peoples houses to get Ghosts and stuff. I imagine there will be a lot of missions where you get ghosts, get paid, get upgrades, etc.
Sounds like Destroy all humans, just where the humans are ghosts.
Oh, and does anyone else absoulutely hate the camera? Not being able to see where I'm going it going to be so awesome!