Super Mario Bros. 3

27 "P" Wings
Complete the game and press UP, UP, DOWN, LEFT, RIGHT, LEFT, RIGHT,
A, B and START. This will give you 27 P-Wings.
     
Extra lives
At the end of a stage, do a super run into yhe black area, when the
whistle blows hit the card and you will get a star. Keep repeating
this to get extra lives and points.


Warp wisthles:
The first warp whistle is on world 1-3. Go to the white block 
sourrounded by four other coloured bloks, then crouch down for
five seconds on top of it. You will fall through behind the
background - run to the right and you will eventually reach a
house. Toad will give you the first whistle. The second is in 
the first world's fortress. At the end of the first section, fly
up to the roof, get on the top and run to the right. When you 
stop, rpress Up - you will now enter a door leading to the second 
whistle. To got to world 8, blow one whistle to get to the warp
section, then blow it again and you're in world 8.