Bonus levels:
After completing the game, an extra level for each world will appear.

Finish all eight levels in each world with a 100% completion to unlock a ninth level in each world.

Bonus games:
Hold Select and press L(2), B, A, R at the level selection screen. A list of bonus games will appear. If you win the selected game you will get a prize.

Lucky 777:
Get your total points for a world to equal to exactly 777, to get 7 extra lives.

Special Yoshi eggs:
To get special Yoshi eggs with out having to find special boxes, fire a Yoshi egg in an area that will cause the egg to bounce off the walls and back to you. When the egg returns to you, quickly use Yoshis tongue at the egg. If successful, you should have a special Yoshi egg.

Level 1-7: Extra lives:
Pick up a Rollie-Pollie Guy with your tounge. Do not turn him into an egg or spit him out for anyone until you get to the pipe that spits out Shy-Guys. Once there, spit the Rollie-Pollie Guy out into a 1 (square) hole on the right of the pipe. Once placed, jump onto the platform above and to the right of it. Let the Shy-Guys jump out of the pipe and onto the Rollie-Pollie Guy. Points will accumulate and will eventually give you 1-Ups continually. After a few hours, you will have 999 lives.