Guessed by drbunnig
You don't need cutting edge power to make a great game. This has been proven time and time again. During the 7th Generation of Video Games, Nintendo's underpowered Wii could still deliver what is arguably the prettiest game of the generation. Of course, there's no way it can compete on a pure, base technical level in number of pixels and particles and polygons on screen, but it could through stellar art direction. Pun intended. Personally I think Nintendo's core teams are very talented in this regard in general, but sometimes they release something that can really stand out from the rest.
'Super Mario Galaxy' was such a game. During the 6th Generation of Video Games I fell out of the console gaming sphere due to one too many disappointments, but the 7th Gen reeled me back in with games such as this one. The rest of the world seemed to agree, as proven by the game's raving reviews. The sequel, 'Super Mario Galaxy 2' was also top of its class, but the first game had something extra special. This time it's not necessarily because it was merely first, but because the game's levels are connected through the Space Observatory hub world, and the hidden, but not so hidden, touching and greatly illustrated story of Rosalina and Luma. Rosalina by the way, also a great addition to the Mario character pantheon. She's a keeper.