The issue with critical game reviews, is the approach of attaching a numerical rating, because with the passing of time the game itself changes, and our contemporary critique becomes detached.
How does a videogame itself change over time? Let take for example the Mario series, started out as 2-D sprite, side scrolling platformer with its' contemporary being a 3-d adventure played on a sphere. Super Mario 64 and Super Mario Galaxy are two great games, based on a 3-D engine that scored roughly the same, with Edge Magazine giving a 10/10 and Gamespot placing a 9.4 and 9.5, respectively, scores. If I were to replay Super Mario 64, I would recognize the charm, and the great joy that I experience in September 1996. I fearfully cringe at the though of missing Super Mario 64, only to return to it in 2009, coming away from the experience as being a stepping stone or an innovator for 3-D platformers.
Both games are very similar in nature, 3-D, Mario controls the same, ice levels are slippery and boo shy ghosts chase when not seen. These two games are, undoubtedly, favorites of gamers, but they are unfinished, as to say, another Mario will build upon the familiar and loved gameplay themes. We are playing unfinished copies of our favorite games. If the reader agrees, then placing a numerical value to a critique is pointlesss.