From the perspective of somebody who has actually bought and made it about halfway through the game...
The real hook behind Catherine's story is that it was designed for MATURE audiences. Not Mortal Kombat/Call of Duty mature, but grown-up, paying your own bills, balancing your checkbook mature. If you get off on space marines and headshots, then this isn't the game for you; go play something else. If you're like me, however, and play games because they tell great stories and challenge you, then this is definitely worth your money.
Also, don't say this game is easy just because you made it through the demo. Some of the levels are fiendishly, yes fiendishly, difficult. You will replay levels a lot, and they will only get harder as you go. For me, the difficulty only made me want to try harder just to find out what happens next. I really care about Vincent's plight, primarily because his character is very human in his thoughts and actions. It really feels like he's reacting to his situation the way a real person would.
Overall, this game does what it sets out to do extremely well; the story is engaging, the gameplay is cerebral and challenging, and it has earned its place as one of my favorite games even though I haven't even finished it yet. Really, my only problem with the game is Katherine (Vince's girlfriend) is a little too much of a *****. I would have preferred if they had given her a slightly nicer personality. Regardless, it's good. Get it.
