Here's a great write-up on SMG from next-gen.biz, definitely worth the read.
Full articleWhatís surprising is how familiar it is, and yet how utterly fresh it still feels. Every previous game in the series seems to have been considered as a possible source for new material. It views and uses one of the most venerable histories in gaming as only a truly confident title can, and is something you want to prod and poke and simply play with. No one yet knows if Galaxy can maintain the momentum and range of its early showings, and avoid the repetition that marred Sunshine. No one yet knows if it will be able to thrive on the unavoidable comparisons to one of gamingís landmark titles. Theyíre unfair, in a sense, because nothing can ever match up to that moment when you set your eyes on Mario 64; nothing ever could compare to that change in dimension. But Super Mario Galaxy has something of its own. Itís the sense of a universe of possibilities with everything you can imagine, and more that you canít. Itís a sheer joy. Itís the sense of something you thought may have been lost to videogames returning. The feeling of wonder might, just might, be coming back.