It happens every time a new game is announced. Every time people start discussing what the final product will be like, specially if it is new IPs. They start discussing graphics, gameplay mechanics, story. Every single aspect of the game is discussed. But instead of discussing what we have, we discuss what we want. And that single difference can kill a game.
Those expectations of what we want a game to be instead of what the game is looking to be hurts. I am not talking about hype here. I am not talking about having so big expectations, unrealistic expectations, that there is no way the game in question will deliver what is expected. i am talking about realistic but misguided expectations, the kind of expectations that make otherwise great games seem as not so good, because it is not what you wanted it to be.
Like wanting a game to implement a gameplay mechanic that you always wanted and discovering that it don't. But instead of being happy if the game implement its own mechanics well, you despise it because it is not the mechanics you wanted to be implemented. Or the fact you created a whole story for the game with the few videos, demos and pics available and getting frustrated because the story, no matter how good, it is far from what you spend days imagining.
You can always find someone who is being unfair with a game when they use words like 'what could have being' or 'wasn't what I expected' or even 'If they have did this and that'. No. A game must be evaluated not by what it haven't done, but by what it do. Not about what you wanted it to be, but by what it is.
Every time I see a review or any article saying that if a game have did something that would please that particular writer, I know I must not consider what he is saying. Because it is not about what the game do right and about what it do wrong, but what the writer wanted the game to do and is disappointed because it don't do.
I understand that everyone have his/her perfect game in its head, but this kind of expectations will only disappoint you. Great games will not looks so great because it is not what you wanted, and this is something so personal that no game will ever accomplish it, unless you make it yourself.
Games must be evaluated by what they delivered, not by what you wanted. It must be evaluated by what they are, never by what they aren't or they should have being. Unless you do that, you will never find games good enough. They will always lack something. And this will always lessen any enjoyment you could have.