I think there is an interesting point of principle that could be discussed here: Exactly who are the game reviews written for?
In this case, we have two separate groups: People who have already played the previous Katamari games, and then those that haven't. Which group should be mostly focused on when writing the review?
On one hand, the first group might well want to know whether or not there are any substantial changes to the game formula. And if the changes (if any significant) are for the better or worse.
But, on the other hand, there will be plenty of new gamers who hasn't tried out the Katamari games; especially since this one is on a different console than the previous three games. Yes, there will be some console overlap, but I wouldn't base my reviews on spending time trying to figure out just how big that is. So, shouldn't the reviewer, insofar it's possible at all, at least try to imagine how this game will feel for someone who hasn't played it?
It will of course, be a matter of balance, as both of these points needs to get out. And as I read GR's review of
Beautiful Katamari, it was easy enough for me to gleam the information I needed (as someone who already has one of the games), while the grading (and reasoning behind it) seemed to be curtailed for how a new Katamari player would feel it, maybe a little bit influenced by the fact that the reviewer's earlier experiences.
Of course, the balance might not have to be the same everywhere. A sports games series with annual releases, for example, may well be more likely to have a lot of recurring buyers. Or, say, Guitar Hero: Rocks the 80s, which most definitely was bought almost only by people who owns at least one of the previous GH games, not to mention that it was released on the same console as GH 1 and 2. To go a bit short on the gameplay mechanics (which was completely unchanged) and focus on the setlist would be perfectly acceptable for that game.
Anyway, I'm fairly certain that any reviewer worth his/her salt is pondering these points. And if they aren't, then hopefully Duke's wrath will rain down upon them.