I only played the demo but I actually thought the game was pretty good. The controls seemed tight, the action and feel of the game was fun and satisfying and the production value seemed pretty polished. The story seemed like it had potential and based on such a famous piece of literature I'm sure it was decent at worst. Had I not played the GOW games already I would have thought this game was amazing, but since I had I just think it's a fun game that did a good job on expanding the GOW experience with different characters and story. How much I'd discount the review score for being similar to GOW I'm not sure but from a standpoint of enjoyability, I felt it was more than adequate for an 7.5/8 score. If I had never played GOW I might have been wowed into giving it a 9. ANd since many gamers out there, especially young ones, have not played the GOW games before, then the game would be a 9 experience for them.
I guess as the video game industry moves forward the merit to reviews are tending to diverge into two directions. Review as a praise for something new and fresh and something artistic or review as a praise for something that is just flat out fun for the casual fan. Should a game be docked for unoriginality? I guess if they are reviewing the game on the bases of artistic praise but if the game is being reviewed for how enjoyable it is. Fun is fun whether it's been done before or not.