I was thinking of doing a review for some games and was wondering exactly what do you people think should be the content of a review?

some examples of what I am looking for is
do you think there should be a lot of opinion about the game?
or do you think it should be more factual and how well it compares to others in the genre also
some ppl Like to do reviews based on different parts of the game
such as Gameplay, innovation, Graphics, Multiplayer, sound etc. do you think it should be reviewed like that and if so what should it be broken up into?