All this is easy to take for granted - the kind of accomplishment that, by its nature, is invisible. But make no mistake, there is exceptional craft on display. Nintendo shows an easy, confident command of concepts that almost any other developer would struggle to think of or articulate, never mind realise, never mind perfect. You simply will not play a better-made game this year.
It's by far the tastiest audiovisual treat on Wii, too. Impeccably solid and fast, it chucks its fruit-coloured and fuzzy-textured planetoids around the screen with abandon, and sets the starlit spectacle to another classic soundtrack of thrilling, orchestral themes and chipper chiptunes.
But a slick finish, structural overhaul and brace of novel features are the stuff all sequels are made of, and on their own, they don't qualify Super Mario Galaxy 2 for greatness. To step out of its predecessor's shadow and justify this second spin of the wheel, it has to deliver surprise, delight, devious challenge and raw creative brilliance, level after level after level.
It does. In Puzzle Plank Galaxy, meandering buzzsaws cut platforms away under your feet. Cosmic Clones appear that ape your every move at second-long intervals until a level is swarming with deadly echoes of everything you've done. In Boo Moon Galaxy, a flat planetoid rears up into a pop-up book of platforms. Rhythmic "beat" levels switch gravity alignment or platform arrangement, or turn the lights on and off to the metronomic tick of the remote speaker.
Flipsville Galaxy is two 3D levels at once, stamped on opposite sides of the coin, Mario pounding platforms down on one side to raise them on the other. Another later level has Mario swimming through cubes of water as they scroll through space, stretching the logical illogic of the game's physics to the limit. In the very best platform games the heroes are the platforms themselves, and Galaxy 2's - ingenious, devious, always surprising arrangements of action and reaction - are no exception.
As with the previous 3D Mario games, after defeating the last of the inventive, testing and fun bosses, you could still have almost half the 120 stars to collect. Galaxy 2 has even more surprises in store for the long-haul gamer, with total completion adding a secret green star in every one of those 120 level variations, doubling the length of the game.
Before that, you'll have discovered another secret extension of Galaxy 2's universe that, in true Mario tradition, reaches beyond childlike surrealism into a wholly abstract realm of extreme gameplay challenge that's as vicious as it is playful. The game might feel more compact than the first, but it's longevity is even greater.
While the New Super Mario Bros. games have been content to remind us of Mario's roots, Super Mario Galaxy recast him in the role of fearless explorer, leaping into impossible realms, redefining what we could do in virtual space. Here, once again, was the Mario of Donkey Kong, of Super Mario Bros., of Super Mario 64.
A simple extension of the Galaxy concept, Super Mario Galaxy 2 can't possibly have the same impact. But it does have the same spirit, throwing new ideas at you with gleeful and impulsive abandon, leaving you breathless, scrambling happily to keep up. You can't really complain about more of the same, when the same is the one thing it never is.
10 / 10