Beautiful colours.
Mario 64, anyone? If you played that seminal game, Mario Galaxy's star hunt progression probably sounds familiar to you. But apart from that basic structuring, you can hardly call Mario Galaxy a Mario 64 rehash. If anything, Mario Galaxy simply takes the basics of what made Mario 64 such a dynamite game, and turns them completely crazy.
The definition of crazy here has a lot to do with gravity and physics. Each galaxy contains a series of little worlds that can't even really be called planets so much as they are floating puzzles. In many of these worlds, Mario can walk just about anywhere. When he lands on a sphere, he can walk all over it, going sideways and upside down in the process. Sometimes you'll simply jump in one area and end up gravitating toward the ceiling or walls or even another nearby planetoid without even realizing it. Often Mario will need to track down launch stars, which, when you shake the Wii Remote while standing near or inside one, will send you flying to a whole new, previously inaccessible area. There are even sections where you'll be floating through space, using specialized pull stars to hop from area to area, all while floating through the spatial void.
Practically every galaxy you explore is an absolute joy to experience. The level designs here are top flight in every regard, with tons of clever and sometimes dastardly traps and puzzles for Mario to navigate. The difficulty doesn't start off terribly high, but as time goes on, the game ramps up nicely, building the challenge steadily until the final areas, which, though perhaps a bit frustrating to inexperienced players, provides the exact sort of tough workout you've come to expect from a Mario adventure. But even aside from the challenge level, simply exploring all these various galaxies is half the fun. Whether you're floating from land mass to land mass on a giant spinning flower, running frantically around a giant series of platforms that shrink to nothing the first time you touch them, or taking on one of several terrific 2D side-scrolling areas reminiscent of New Super Mario Bros. for the DS, you won't be wanting for variety while playing through Galaxy's dozens of levels.
In a sort of nod to the suit-happy gameplay of Super Mario Bros. 3, Mario can don a number of different costumes that give him new abilities. For instance, in several levels, Mario can take on the abilities of a bee, buzzing around through the air via his new pair of wings, and wall-climbing specific honeycombed areas of the environment. With others, Mario can freeze water to walk over it, launch fireballs (natch), fly, wrap himself in a Mario-sized spring and jump to great heights, turn invincible (natch, again) and even turn into one of those pesky boos, allowing him to float around and pass through some solid walls. In most cases, the game takes great advantage of these abilities in the context of each level. A few involving the bee suit are a bit frustrating (given that you lose the suit when you touch water) and the spring suit is kind of a pain to control given Mario's perpetual bounciness, but otherwise, these abilities add a great dimension to the already excellent gameplay