My dear Laura, even when you are right about what art is, the big difference is that when you buy it, you have already seen it. One of the big problems of mass effect is not only the ending is that the choices we made are not reflected at all in the ending of the game. When someone offers you a RPG like game with decision making and you already saw how it affected the game in previews versions, you expect on your new piece of "art" what you saw in previews versions. It's like selling a beef sandwich made but the most famous cook and somehow you got chicken...should I be satisfied just because is his "art".