Open the House next to Taste-T's:
Go underground to where the entrance to Shiver City is. Instead of going through the blue door, go all the way to the bottom-right corner of your screen; there you'll see a green pipe. Go down it. There may not look like anything down there, but take Bombette and have her blow up the wall on the right hand side. A hole will appear, go through it. There will be a guy that tries to sell you stuff for 64 coins a item. Again, go to the far right of the screen, you will see another green pipe. Go through it and you will find yourself in the house next to Taste-T's. Get the key and unlock the door; now you can enter the house from the outside.

How to beat Tutankoopa:
Buy 9 thounderbolts and use them all on Tunankoopa. Then use Parakarry's Shell Shot.

Get the Hammer Throw Badge:
Right before you go in the hall to Toad Town, look at the tree above. It should have a spring (jump). Hit the tree with the hammer. The jump will fall and you will get the Hammer Throw Badge that lets you hit anybody in battle with your hammer.

How to beat the Dojo Master in one shot:
Go to Mario's house and spin into the next scene, and beat every other Goomba you find, ending up in Toad Town, go to the Post Office and read a letter ten times, and go to the dojo, and the Master will glow a neon red, he will be extremely weak

Infante Goomba Nuts:
Go to Goomba Village and hit the tree beside the fence. You will get a goomba nut. You can do this infante times. Just leave and go back in.

Original Mario Cameo:
To play as the original Mario (the blocky pixelated not so cartoony version of him) go to the ground floor of Boo's Mansion and go through the first door on the right. Inside, jump into the vase in the left hand corner. He will be the classic Mario when he comes out but will change back as soon as you leave the room.

Hidden room:
There is a hidden room in Toad Town where you can play games to earn cash. To access the room, go South in Toad Town until the Li'l Oink Farm. To enter the room, go left when you enter this area. Strike the tree with your hammer and a pipe will become visable on the right. You can now enter the room. You must hold either a Silver and/or the Gold card to play.