Let's begin with what the game has for the newcomers. If you're not completely competent at the kind of 3-D "platforming" (game play that has you jumping from platform to platform) persistent in "Mario" games, an innovative two-player cooperative mode is the way to go.

First, you'll have to know the story. Mario has to travel from galaxy to galaxy in order to retrieve Power Stars and undo the evil perpetrated by Bowser, Mario's longtime nemesis. There are 120 Power Stars hidden on the planets of the various galaxies.

These aren't planets the way we normally think of planets. Often, they're small orbs of space rock or odd-shaped pieces of space junk. A "galaxy" might be made up of anywhere from five to 25 planetoids of varying shapes and sizes _ and gravitational pulls.

Mario can walk all the way around (and underneath and even inside of) some planets without falling off. Others are more ledgelike in nature, and Mario might go spinning off into space if he misses a step or a jump. Figuring out how to use the varying gravity while you explore a planet and then hop, skip, jump or rocket to other planets within a given galaxy is half the battle. Fighting and retrieving Power Stars from the "boss" enemies and minions who inhabit the planets is the other half.

Two-player mode puts control of Mario in the hands of the first player and point-and-assist control in the hands of the second player. You'll need a Wii Nunchuck peripheral for the first player's remote. The thumbstick on the Nunchuck makes Mario walk and run around planets. The A button on the remote makes Mario jump. Waving the remote makes him perform a spin attack. Sometimes he will find special suits that turn him into a flying bee or a floating ghost so he can investigate otherwise unreachable areas.

The second player can use his or her remote like a laser pointer. A star-shaped icon pops up on the screen wherever you point the remote, and you can help the first player by boosting their jumping power, grabbing enemies, moving dangerous objects or even shooting "Star Bits" at enemies to stun them. Just point and click to assist the first player. This is a great way for parents and young children to explore the game together.

If you're a veteran of "Mario" games, you'll want to go it alone, although it is nice to have a second player to collect Star Bits by pointing at them. You'll collect the traditional gold coins found in most Mario games, but Star Bits are the game's main currency. You can use them to buy power-ups and special items. Or you can feed them to the starlike Luma creatures who will then shoot into space and transform themselves into new galaxies to explore.

As I mentioned, there are 120 Power Stars hidden throughout the universe. Finding enough of them to get you through the game's story mode is difficult. But finding all 120 is going to keep even hard-core gamers busy for a long time. Often, you'll have to revisit galaxies in order to take on challenges you missed on your first trip.

And then there are the Prankster Comets, which sometimes sneak into galaxies and add challenges. When a Prankster Comet is in a galaxy, your enemies might become stronger and faster, or you might have a limited amount of time to complete an objective. Or there will be some other topsy-turvy shenanigans going on.

In true "Mario" game fashion, some of the tasks required to capture some stars late in the game are going to make you want to pull out your hair. Unlike past "Mario" titles, there are times when the game saves your place halfway through an area so that you don't have to start over from the beginning every time you slip and fall off a planet.