After you save Toadstool in Marrymore, go back to the Mushroom Kingdom. Go to the Inn and talk to the purple toad. He will sell you Beetle Mania for 500 Coins.
Change the Background
In the pause menu, hold L and R and point in a direction with the control pad. Whatever direction you point is the direction it moves. Also, if you save the game the background will stay moving in that direction until you change it later.
In Game Reset
To reset the game, press Start + Select + R + L at the same time at any time.
After Star Hill and before going to Nimbus Land, head back to the Mushroom Kingdom. Go to Mario's right in the guest-chamber (where the toad gave you the Wake Up Pin when Mack was terrorizing the Mushroom Kingdom). Sleeping in the bed is Samus Aran from the Metroid series.
At any point in the game, go to the Mushroom Kingdom. In the first long hall, go to Mario's left. Go straight and you will be in Toadstool's room. Go to the fireplace and to the right of it press A. It says you found Toadstool's ??? If Toadstool is not in your party yet, her grandma will give you a Mushroom.
If you play with Gaz at the Rose Town Inn, you can stay there for free. When you wake up, a green fairy boy named Link from the Zelda series is sleeping there.
Infinite Frog Coins
In Land's End, go to the part with the whirlpools and ants. Jump on the ants 3 times in a row to get a Frog Coin. After the 3 hits, the ant will go down and come back up. Keep jumping on him 3 times in a row as many times as you want.
Three Musty Fears' Flags
In Monstro Town, go to the "Inn", or the Must Fears' bed. While sleeping the 3 Musty Fears will ask you if you want to play "Find the Flag". You have no choice but to play. One of the 3 Musty Fears gives you the clue “Under a green bed” - the flag is under Mario's bed in Mario's Pad. Another's' clue is " Behind a wooden flower" - this flag is behind the wooden flower at the beginning of Rose Town. The last's clue is "Between an A and an O" - this flag is between the A and the O of the word GOAL in Yo'ster Isle. After retrieving all the flags, go back to Monstro Town and sleep again. The 3 Musty Fears will say "He found all our flags" and give Mario the Ghost Medal.
After you beat Megalax in Bean Valley, there will be a note talking about a Seed. Take the Seed and go to Nimbus Land if you've already defeated Valentina. If you have, go to the very right of Nimbus Land. Along the side is an invisible path. Run against the side in different spots and you're sure to find it. After your on the invisible path, a Shy Away will come. Defeat him and he'll give you Fertilizer. After you have both, go back to Rose Town. Go to the very back and there is a new area you can go into. In the area is the Gardener's house. Enter and give the Gardener the Seed/Fertilizer. He will plant them and a beanstalk will grow. Climb the beanstalk and hit the treasure boxes - one has the Lazy Shell (Weapon) and the other has the Lazy Shell (Armor).
Flower Jar or Frog Coin?
After you beat Croco, you get the Wallet. The wallet belongs to the blue resident where the one kid is running around. You can give it to him now, you will get 1 Frog Coin. If you wait a little while throughout the game , you can give the Wallet back for a Flower Jar. However, if you wait too long you get nothing.
Secret Treasure Boxes
In the Forest Maze go to the part where you can go in 4 different directions. Go left, left, straight, and then right - all in Mario's directions. Go down the stump and there will be a lot of treasure boxes.
There are 3 invisible helpers:
1. The first is in Mushroom Kingdom. Go to the very far left - by the house that is by the Chancellor's place. Go behind the house and an invisible guy will give you hints until you reach Star Hill
2. The second is in Rose Town. Go to the house where the treasure boxes and button are. If you go around the house you'll find invisible guy #2. If you have not beaten Bowyer, he will tell you to go away. After you beat Bowyer, he tells you about the Goomba Thumpin' game and Yo'ster Isle.
3. The third is also in Rose Town. Go to the house where a resident is complaining about her husband. Behind the house is an invisible helper. He doesn't really help you - he is just a resident who got hit by an arrow.
This isn't really a secret. In Rose Way, go to the ending part where there are treasure boxes with coins. You can get them all and leave the area. If you come back, the treasure boxes will be full again. You can also go to Bowser's Keep after you've defeated Magikoopa.
In Moleville, you can buy fireworks for 500 coins. They give you more fireworks at the end of the game. You also either get a Mushroom, Fire flower, or Star which depends on how many you buy. If you buy 0-2, you get a Mushroom. If you buy 3-4, you get a Fire flower. If you buy 5 or more, you get a Star.
In Forest Maze, you can find yellow wrigglers. If you jump on them 10 times in a row, they give you 9 coins and 1 Frog Coin.
In Yo'ster Isle, you can race Boshi 1 - on - 1. After you beat him, you can start betting your Yoshi Cookies on only Yoshi. Talk to Boshi and he will tell you Yoshi's odds. You can choose to watch Yoshi or control him as you did against Boshi. If you win, you get more Yoshi Cookies. (Note* - The pink Yoshi who gave you Yoshi Cookies will store them for you). After you get enough Yoshi Cookies, you can feed them to the baby Yoshi. He will give you items like Red Essence, Royal Syrup, and the rarest item in the game - the Yoshi Ade.
Toad the Monster???
In Nimbus Land, go to the Inn. When the guy asks you to use the Dream Cushion for an extra 30 Coins, say yes. It may take a while and waste a lot of coins, but in one dream Toad will appear. He will reveal himself to be a monster. When Mario wakes up from his nightmare, Toad is standing next to his bed. Toad will say you had a nightmare and give you 2 Red Essences.
Sell your Bright Card
In Marrymore, you can sell your Bright Card. Go to the Inn and talk to the first guy on Mario's left. He will ask you to sell your Bright Card for 5 Frog Coins. If you press no, he will offer you 10 Frog Coins. You can sell it to him, but if you want it back you have to pay 15 Frog Coins.
In the Inn at Marrymore you can stay in the suite. For the first 3 times, you get a Flower Box. After you get the Flower Box, every fifth time you get a Frog Coin.
Safety Badge and Safety Ring
In Sunken Ship, go to the part where King Calamari is (The giant squid). Right after he is beaten, your in a room with a save point and a treasure box. Save your game and hit the treasure box. You will now be in battle with one of the treasure box monsters. Defeat him and you will get the Safety Badge. The Safety Ring is also in Sunken Ship. Go to the room with the Blooper and the Blooper Kids. Go underwater and go behind the barrels. Enter the door and hit the treasure box to get the Safety Ring.
Keep the Coins from Midas River
In Moleville, buy the Fireworks. Then go trade them for the Shiny Stone. Go to the store and trade the Shiny Stone for the Carbo Cookie. Go to the left/bottom most point in Moleville. A girl will be sitting on the bucket. Give her the Carbo Cookie and she will run off to get you something. However, she will never come back. Stand on the bucket and press Down on the Control Pad. You will now be in Midas River - except you get to keep the coins this time. If you go back to the girl on the bucket, she will be there. If you give her another Carbo Cookie, she will give you 1 Frog Coin.
In Star Hill, you can talk to the little stars on the ground that have smiley faces. They talk about people's wishes.
First off, you have to have the B'Tub Ring and the Mystery Egg. Equip the B'Tub ring on Toadstool and use the Mystery Egg 10 times. The Mystery Egg when then turn into the Lamb's Lure. Use the Lamb's Lure 48 times in battle to get the Sheep Attack.
Attack Scarf / Super Suit
To get the Attack Scarf, You must Super Jump 30 times in a row. Then go talk the Chow in Monstro Town. To get the Super Suit, you must Super Jump 100 times in a row and then go talk to the Chow in Monstro Town.
8 - Bit Mario
To get 8 - bit Mario, go to Booster's Tower and to the room with the curtains. Go behind the curtains and you will come out as the original 8 - bit Mario. If you go back in the curtains or try to leave the area, you will be transferred back to the regular Mario. You can only do this once.
Free Frog Coin
In Booster Pass, right at the beginning go right. Talk to the bush that's farthest right to get a Frog Coin.
Apprentices Become Snifits
After you hit the switch in Booster Tower, go to Booster Pass. At the beginning go to the left. A new area is now open. Go in the area and an Apprentice will start coming towards you. Let him win and he becomes a Snifit. Keep doing this until you have 7 Snifits. This doesn't affect anything to do with the Mini Games the Snifits is in.
Get the Masher
In Booster Tower, if you go past the desk at the beginning, you will see a teeter-totter with a Bomb-omb. Go a bit further into the tower and there will be a path that will take you into the same room but, higher up. Jump down onto the teeter - totter and you will be flung back up and you will hit the treasure box and get the Masher.
In Booster Tower, go to the room with the portraits. You need to hit them in a certain order to get the key. First, hit the one all the way to the right. Then hit the one closest to it on the left. Next, go 2 to the left and talk to that one. Then go to the farthest left and hit that one. After that, hit the one next to the farthest left. Then hit the last one. You will get the Elder Key. Enter the door and jump towards the Chomp. Bowser will take it as his first weapon.
After Booster Tower is beaten, and when you are exiting, Knife guy will be in Booster Tower juggling balls. You need to guess the yellow ball 12 times to get the Bright Card, however, Knife Guy counts off losses. The bright Card gets you into the casino.
Great Guy's Casino
First off, you need the Bright Card. Go to Bean Valley. In the part where Shy Away grows the piranha plants, go into the pipe farthest up. Then, go all the way to the right of the area. You will now see a chomp. Defeat it and then keep jumping to find a hidden block. Jump on the hidden block and then to the above area. You now have access to Great Guy's Casino.
After you have access to Great Guy's Casino, go there. Keep talking to Great Guy until he asks if you want to play "Look the other way". Beat him 100 times (Great Guy doesn't count off losses) to get the Star Egg. It may take a while, but it's worth it. The Star Egg does 100HP of damage to all enemies and can be used forever.
Culex - Dark Knight of Vanda
To fight Culex, you first need to go to Moleville. Buy the Fireworks and then trade them for the Shiny Stone. Next, go to Monstro Town. Go to the middle door and there will be a seal on it. However, the Shiny Stone will break the seal. You can now fight Culex - Dark Knight of Vanda. (Note* - Make sure your party is leveled up as Culex is the hardest boss in the game).