Instead of just pressing A + B at the main menu of the demo, press and hold 1 + 2 when pressing A + B to access two additional stages.

Get 31 stars go to the middle of the star ring and press a, b, a, b, c, b, z, z, b, c, a then shake the remote 3 times and spin around then u turn into yoshi.

Get all 120 stars. Return to Rosalina on the Comet Observatory and request to fight Bowser again. Finish the credits and you will get a message saying that Luigi is now playable.

To unlock the final star and galaxy, collect all 120 stars with Luigi and beat Bowser. Doing so unlocks the Grand Finale Galaxy, which is the Star Festival seen in the beginning of the game. Collecting the 100 purple coins in this galaxy gets you the final star.

Collect all 120 Stars then go back to Rosalina at the Comet Observatory and fight Bowser again. Luigi will be unlocked as the main character after the credits.

Use a second Wiimote during game play. Although a second player will not appear, the second Wiimote will have its own pointer, allowing another player to assist by collecting items and helping Mario's jumps.

After you get 120 stars as Luigi, you will unlock the Grand Finale Galaxy for both Luigi and Mario, where Star 121 is found after all 100 purple coins are collected."

Collect 9999 star bits in the hub, and all the coconuts in the game become watermelons.

When the countdown timer starts as you are racing Shadow Mario, hold forward, then as it hits 2, hold down on Z to crouch, and when the race starts hit A right away and you will turn yellow for a few seconds and get a really good boost that will put you way ahead of Shadow Mario.

This bullet bill flinging bot is easy and well ok its a bit hard but following these steps will give you the POWA! ahem, here's how to do it...

Dodge the bullet bills and dash up the robots arm. No matter which one you run up, you'll get to the head (cuz thats our target)

When you'ue on the head,notice that theres a flashing thing, so you need to distroy it in order to win.

However, you can't ground-pound or spin to hit the thing,but since bullet bills are chaseing you around, then there the only thin to hit the flashing thing.

Lead them to you when you are near the red thing, then jump if it gets too close to you, then in result the stupid missile will not have any time to turn around and BAM!
IT SMACKS IN TO THE RED THING!!!!However, you ARN'T finished with this one Yet!

after the damage,the robot needs hit AGAIN, but this time it puts up three sheilds to defened the flashing thing. This makes hiting harder than last time, so try and lead the bullet bill to hit it. If it hits it, then BOOM, BANG AND THE ROBOT EXPLODES, AMAZING then the star is yours.

Spin in mid-air then immediately press Z to hit the nearest target.

In the Deep Dark Galaxy level you can use the cannon on the beach for a shortcut. Normally you would need to use the cannon to shoot yourself to the nearby planet to get a Fire Flower then use the Jump Star to return to the beach so that you can light the two torches to open the door in the first star, or the three torches to make the Ice Flower appear in the second star. However if you get in the cannon and turn it all the way to the left as far as it will go, you will see two yellow platforms moving up and down. Watch them carefully. When the farthest platform is up, line your crosshairs up with the side of it. Then, wait until the closest platform goes back up and fire yourself in that direction. If timed correctly, the platforms will have switched again and you will hit the side of the furthest platform and fall on the ground. You must hit the wall or you will overshoot and die. This will put you inside the "bowel" area without opening the door on the first star. If you are on the second star you will not have to worry about getting the Ice Flower to cross the lake and jump the faucets. You can just proceed right and climb the poles to get to the Bubble Shooter.

When you get up to the boss "King Kaliente", the big squid with a moustache. When fighting him he will shoot firballs at you. Between every fireball he shoots he will shoot a coconut. Hit the coconut back at him by shaking the Wii remote. After this he will shoot another firball and then a coconut. Hit the coconut at him. This time he will hit it back to you. You have to run over to where its going to pass and hit it back. When it hits him he will release some little minions, kill them by shaking the wii remote. If by this point you are low on health, run underneath the planet you are on, there will be some little gold things stuck to the ground around a toad. shoot them with starbits to get some coins wich heal you. Run topside and reapeat the same sequence with Kaliente. This time he will hit it back twice though so be ready. After you hit back a second time he will die and leave a star. When you fight him later on in the game you are on platforms that sink into the lava. Simply repeat what you did before except move around on the platforms to avoid being burned. He is only a bit harder then the first time you fight him but still easy. Congratulations you have defeated King Kaliente! (twice)!

All those powers (fire, bee, etc...) On the comet obsovry, look up, down, brake bricks untill you find a black orb (its so black that black backgrounds make it hard to see)

Unlock luigi first, go to ghostly galaxy, talk to luigi, obian the star, head to battle rock galaxy, try and find luigi, talk to him, he'll say "Oh,its you. Well i found this star." He'l throw it in to the air. And the star will be green.

The rocket mario power up is available in the lobby and the first level, go to the first level (the gate) when it becomes available (when you unlock the last observatory at the top) You will meet a red Luma (after a cut scene) Do the red lumas callenge by collecting all 100 purple coins, then the Rocket power up will be available in the lobby in two places.

Go to the 2nd mission. Go to the planet with the huge screw in it and on one of the planet's sides, there'll be a hungry luma. Feed it 50 starbits and it'll transform into a planet. On the planet, you have to activate all the panels (it's hard. TRUST me.) When they're all activated (yellow,) a star will appear (the hidden star.)

In Buoy Base Galaxy, above the tower where you collected the Blue Star Pieces, is a little planetoid that is a sphere with two red panels on top and a lighter bottom with a screw in the middle. It looks exactly like a Pokeball.

One of the planets is shaped like Captain Olimar's rocket ship that appeared in Pikmin and Pikmin 2.

In Buoy Base Galaxy, above the tower where you collected the Blue Star Pieces, is a little planetoid that is a sphere with two red panels on top and a lighter bottom with a screw in the middle. It looks exactly like a Pokeball.

(easter egg) if you go to the first bee galaxy as you land turn and look away from the planet you should see star bits in the shape of an M.

hint when doing a cosmic race at the start hold the nunchuck forword hold Z and when it says go press A for a boost at the start.