It's the apocalypse, and you're wearing a bumblebee costume.
Well, it's an apocalypse anyway. Out here, in the bright depths of space, Mario Galaxy wants to show you the end of a universe. And - sorry to break this - it's a universe you probably know so well. 11 years after Nintendo's designers revealed the true potential of the 3D platformer with Mario 64, Tokyo EAD would essentially draw the genre to a close, taking the simple business of running and jumping to places that running and jumping had never been - and at times moving beyond them both entirely. Your expectations would never be quite the same again.
Sure, people would still release 3D platformers after this (and Nintendo would definitely release more Mario games, too), but somewhere within Galaxy and its sequel I think there's the unmistakable sense of a great idea reaching its fullest, and perhaps final, expression. Mastery is often a dead end, isn't it? Still. What a way to go.
Galaxy begins with a gentle statement of its astonishing scope. The opening sequence presents the Nintendo equivalent of a powers-of-ten shot, snatching you away from the familiar surface of the Mushroom Kingdom before dropping you high overhead on a beautiful lumpy planetoid covered with felty grass and shimmering puddles, where three bunny rabbits are waiting to lead you on a treasure hunt.
There's time to register how different this all feels - stuck to the surface of a sphere while a camera roves unmolested above you - but before long, Nintendo is moving outwards once more. Now it's unveiling the first of a million plasticky launch stars and blasting you far beyond the rabbits and the grass and the puddles and into a glittering archipelago of floating space rock, home to a handful of scattered moons. Each of these moons is as pretty, as mysterious, and as playful as the place you've already spent 10 minutes exploring. Each is yours to claim, and beyond this archipelago, dozens more await your arrival.