Luigi:
To unlock Luigi, collect all 120 stars. Go to Rosalina on the Comet Observatory and ask to fight Bowser again. Defeat him to unlock Luigi.
Grand Finale Galaxy:
To unlock the Grand Finale Galaxy, with Luigi, collect all 120 stars and defeat bowser. The Grand Finale Galaxy is the Star Festival seen in the beginning of the game.
Star 121:
To get the 121st star, collect 100 purple coins in the Grand Finale Galaxy. The 121st star is the final star. Your saved game file will now display how many lives you have lost.
Watermelons instead of coconuts:
To turn coconuts into watermelons, collect 9,999 star bits in the hub.
Flying Mario:
Get the sixth grand star to open “The Garden” and “The Gate” domes. Enter “The Gate” dome and talk to the red Luma who will challenge you to get all 100 purple coins and give you a red star that makes you fly after spinning in midair. After completing the challenge, red stars will appear in the observatory.
Higher jumps:
Perform a triple jump, and at the peak of your third jump spin to jump even higher.
Homing attack:
While in mid-air, spin and press Z to hit the nearest target.
Super ground pound:
To perform a super ground pound, jump and spin. When you see the light, ground pound to make Mario do a cannonball then slam on his legs with his hand raised. It is more powerful than normal spins.
Second Player:
If you have a second Wii controller, you can have a friend play along with you. While there won’t be a second player on-screen, you will have a second cursor to use. This means that Coins, Star Bits, and the like can be collected by the second player. There’s also some functionality in controlling Mario’s jumps.
Extra Lives:
You start each game with only four lives. There following are five more lives in the Observatory that you can acquire:
1. On the moving green platform below the core.
2. Under the stairs leading to the kitchen.
3. Right at the top of the observatory(after unlocking the red star).
4. Underneath the entrance to the gateway to the stars(after unlocking the red star).
5. Next to the StarShroom in a crate.
Green Star Locations:
Battlerock Galaxy
After rescuing Luigi from the haunted mansion, he’ll start helping you find power stars. The second star he finds is on Battlerock. Go rescue him and get the star.
Buoy Base Galaxy
As soon as you get there, dive underwater and get the underwater missiles to hit the cage blocking the green pipe. Head down there, and you’ll pop up on the bottom side of the plane. There will be missile launchers everywhere, so make sure you have full health and good jumping skills. The star will be inside. Get a missile to hit it and you get your second green star.
Dusty Dune Galaxy
On the second level of Dusty Dune, where you start, right underneath is a Hungry Luma. Feed him the amount of star bits he wants, a new planet will form and a launch star will shoot you there. Now, you must collect all 5 silver stars. This part is like an elevator thing; you land on the button and you go up or down go in every direction you can until you have all 5 silver stars.
View lives lost:
To see how many times you have died, collect the final star in the Grand Finale Galaxy with both Mario and Luigi. The information for your saved game file will now show the number of times you have lost a life.
Garbage dump star in Battlerock Galaxy:
The game will tell you where to place the bombs for the most effective blast patterns. Place a bomb on each yellow circle (the ones you shoot to make a coin) to blow up all the garbage.
Pokemon easter egg in Buoy Base Galaxy:
Go to Buoy Base Galaxy. Above the tower, where you collected the Blue Star Pieces, is a little planetoid that looks just like a Pokeball. It has a sphere with two red panels on top and a lighter bottom with a screw in the middle.
Extra lives in Comet Observatory:
-At the Comet Observatory, run around and collect the 1-Up Mushrooms. When done, go into a Dome and come back out. All the 1-Up Mushrooms will appear again. Note: More 1-Up Mushrooms will be available once you unlock the Red Star.
-There are five 1-Up mushrooms at the Comet Observatory. The first is behind the base of the kitchen, the second is in the box at the garage, and the third is under the library and bedroom (only one mushroom here, not two). The fourth and fifth require the Red Star to appear. One is under the gateway while last one is at the very top of the observatory.
Shortcut in Deep Dark Galaxy:
In Deep Dark Galaxy, you can use the cannon on the beach as a shortcut. Get in the cannon and turn it all the way to the left as far as it will go. You should see two yellow platforms moving up and down. Watch them carefully and 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. If done 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 die. This will put you inside the “bowel” area without having to open the door on the first star.
Garbage Dump star in Dreadnought Galaxy:
This star is difficult to get because the bombs seem to explode too late. First, place a bomb on every little yellow circle that you shoot to make a coin. You?ll need six bombs to provide the best blast coverage. When the level starts, long jump to the left-most bomb. Take it and run forward a bit before throwing it at the furthest left side yellow dot. Next, long jump back to the second bomb (from the left) and take it. Turn around and throw it, making sure it lands just about on the left side middle dot. Get the third bomb and do the same. It should land just about on the right side middle dot. Next, take the fourth bomb and run forward a bit before throwing it at the furthest right side dot. Long jump back to the first bomb again, which should be just barely shooting out another bomb. Take it and throw it at the closest left side dot. Finally, get the second bomb from the left and toss it at the closest right side dot. When you pick up that last bomb you should have around fourteen seconds remaining on the clock. You need at least eleven seconds. Make sure you take the second bomb for the closest right side dot because it lights when you pick it up. The bomb will already be active while you run to the dot. Also make sure to get the bombs as close to the yellow dots as possible and execute all your moves flawlessly since every second counts. This will require some practice and experimentation as to how far Mario can throw the bombs.
Defeating Cosmic Mario in Honeyhive Galaxy:
-Hold Forward before the race begins while pressing Z to crouch when the timer reaches “2”. Immediately press A when the race begins. If done correctly, Mario will turn yellow briefly and get a faster start.
-When racing against Cosmic Mario, perform long jumps to reach the goal faster.
Easy star bits in Rolling Gizmo Galaxy:
First, go to Rolling Gizmo Galaxy with either Mario or Luigi and get plenty of 1-Ups. Then collect every star bit you find. This may take a while but you can get 999 star bits easily without going to multiple galaxies.
Easy star bits Sling Pod Galaxy:
There is a comet at this galaxy with a lot of star bits. Grab onto the nearest grey tree and collect all the star bits. You?ll earn an extra life from all the star bits. After collecting all of the star bits, intentionally fall into the black hole. You won?t lose a life because of the previously awarded extra life. You will respawn at the last grey tree you were on. Collect all the star bit again and repeat, Each time will earn you around fifty star bits.
Extra lives in Space Junk Galaxy:
In Space Junk Galaxy, select the Tarantox’s Tangled Web star and play through the level until you get to the glass-covered planet. If you have not already done so, feed the Hungry Luma fifty Star bits. Use the Launch Star to go to the Yoshi head planet. Now, without killing them, collect as many Goombas as you can and get them to follow you. You will need at least eight of them. Jump and bounce on them without hitting the ground. A number should appear that counts up to “7? and the eighth Goomba you will start receiving extra lives for every Goomba you bounce on. It?s possible to get more than ten extra lives each attempt.
Pikmin easter egg in Space Junk Galaxy:
If you look closely, you?ll notice that one of the planets is shaped like Captain Olimar’s rocket ship from Pikmin and Pikmin 2.
Sleeping Mario:
Allow the game to idle for about one minute and Mario will fall sleep.
Bowser strategy:
While running up the stairs to face Bowser for the final time, collect the 6 Life Mushroom and the Life Shroom. You will first be on a sphere with spiky plants while Bowser rolls into a brick ball and chases you. When he is nearby, spin to hit him. Do this twice. Next you will be at a rock with little plants and he will breathe fire. Protect yourself by hiding behind the plant things. He will then curl up into his spiky shell and come at you quickly. When he is close, hit the plant thing at him. Do this until you end up where you usually fight Bowser. Make him ground pound the glass and burn his tail. Hit him once, then hit him again when he is on his back. The last time you do this he will spin much faster. Time it, then hit him. Grab the final Grand Star.
Flip the screen:
Note: You must have the Engine Room dome unlocked. Go outside of the dome and move slightly to the left. Jump off the platform and slide down the curtain. After falling off the curtain, immediately Ground Pound and fall into space. A bubble will carry you back up to the Engine Room. While you are going up, the screen will flip for about two seconds. Note: This doesn?t work every time.
Rosalina’s bubble:
Go to where Polara and Rosalina stand together near the beacon. Stand far enough away from Rosalina so that the talk sign doesn?t appear. Then, try to jump on Rosalina. A bubble should form around her.
Hurt Rosalina:
Go to the room where Rosalina is standing. Then, zoom in, aim at her, and press B to fire a Star Bit at her. When it hits her she will get scared and jump, and it will hut her.
Wrong costume when hiding:
-Become Bee Mario and walk behind an object such as a wall. You will see a black outline of Mario. However, the black outline is of Mario?s regular clothes instead of the Bee costume he is wearing.
Jump towards the Beacon without being carried back to the platform:
Perform a long jump towards the Beacon (the big yellow ball off the platform where Rosalina is standing). If done correctly, you will land under the Beacon but won?t be carried away until you slide further away from the Beacon.