Successfully complete the game to unlock Expert Mode and Plus Mode. Unlock the door to get Mini Mario. Also, when you collect all the presents and complete a level, you can play an extra game. There are two games in all, and are selected randomly.
Mario's Food Dreams
When you get a game over on a World, allow the game to idle for a few minutes. After awhile, Mario will fall asleep and mutter his favorite foods, such as ravioli, pasta, and others.
Fruit
Run into fruit on vines. The fruit will fall and will kill the enemies in its path.
Avoid Losing Lives
When you are about to die, turn off the Game Boy Advance.
Stuck In Level In Level 4-3 Glitch
When you go to the second half, go to the right of the screen. Get on the spring and jump to the right. You will jump out of the screen and cannot get out unless you restart the level.
Level 49?
After you beat all of the levels, you will go to the FORTY-NINTH level! There you will fight DK with giant barrels.
Unlock PLUS worlds and expert levels
After beating the 1st 6 worlds, and the end Donkey Kong boss, you'll unlock 6 new PLUS worlds. You will also unlock the option to choose EXPERT at the main menu. There are some expert levels, and each require a different number of Stars (that you achieve by getting high scores in the normal/PLUS game) to play.
Bronze Mario Crown
Get all the stars in one world.
Golden Star Crown
Get all the presents in every Expert level.
Silver Mario Crown
Get all the stars in both worlds.
Unlock Expert Worlds
Beat the first world to open Expert World, then collect stars to gain new levels.
Effect - Code
Level X-1 - Get 9 stars
Level X-10 - Get 90 stars
Level X-11 & 12 - Beat the first 10 worlds with all presents
Level X-2 - Get 18 stars
Level X-3 - Get 27 stars
Level X-4 - Get 36 stars
Level X-5 - Get 45 stars
Level X-6 - Get 54 stars
Level X-7 - Get 63 stars
Level X-8 - Get 72 stars
Level X-9 - Get 81 stars
Unlock all eight movies in the Visual Options menu
View these movies in the Visual Options menu after unlocking them in the game.
Movie - Task
Movies 1 and 2 - Start a new game
Movie 3 - Get to the boss of the first world
Movie 4 - Beat the boss of the first world
Movie 5 - Start world plus
Movie 6 - Get to the boss of the world plus
Movies 7 and 8 - Beat the boss of world plus