First of all, it wasn't intended to be an RE clone. So why in the hell would it use the same engine, or even be compared to the series?
Second, the story was actually really well done, and intriguing...but you wouldn't know that, since you admittedly didn't get very far at all in it. The gameplay was spot on, the variety of weapons/items, and enviroment interaction was incredible....the branching stories, the multiple paths, the difficulty, etc....were all done well. On the surface the game seemed very shallow, and simple...but it was far from that. As you played further, it became pretty damn deep. Not to mention, the replay value is out of this world.
It wasn't a perfect game, far from it....it certainly had flaws. But it was one of the more interesting, and fun game of the year.