I think reviewers often unfairly bash the multiplayer portion of the game. Of course its not as good as the rest of the game, but they still use it as an excuse to dock it points.
Nevertheless, still an amazing score, EGM gave it a 9.0 9.0 10.0 I believe. Looks to me like the good people at Retro have done it again.
Oh and BTW, you can download the new commercial for the game at the offical website,
www.metroid.com
Although you will have to do a bit of scanning around to find it within the website...cool commercial though.