Walk through walls
                      
In 1-4, pass the first firebar thing and stop on the next platform. You'll
notice that the ceiling drops down and almost
                      
forms a wall. Slowly go to the right until there's about half a block length
between the left edge of the screen and that
                      
wall. Direct Mario to the left side of the screen, and jump. Mario should
hit his head on the ceiling and land on the wall.
                      
(If Mario can't fit, you've scrolled too far. If Mario doesn't get stuck,
you haven't scrolled far enough.) Now, hold Left and
                      
jump rapidly until Mario starts moving backwards through the wall. At this
point, you'll be able to walk through to the end
                      
of that low ceiling (beware the firebars...). It is possible to repeat
this trick anywhere you find similar floor/ceiling/wall
                      
combinations.
 
 
                      
Un-Fiery Mario
                      
(This is sort of related to the "drown bug" listed down at the end.) Bring
Fiery Mario to a water level. Stand on the sea
                      
floor and hold Down as you press A to swim up again. You won't be able
to shoot fireballs until you touch the floor
                      
again!
 
 
                      
Minus World
                      
World -1 (A.K.A. the "Minus World") is an infinite water level, only accessible
through World 1-2. Here's what you do:
                      
As Super Mario, get all the way to the green pipe at the end of 1-2. Stand
on top of the pipe and smash the blocks
                      
above you. Do not smash the very last block on the right. Now, stand on
the end of the pipe and face left. Jump straight
                      
up, then press and hold Right on the controller. What you are trying to
do here is jump through the bottom left corner of
                      
the block backwards. If you do it just right, Mario will slide through
the block and be pulled through the wall. When
                      
Mario gets to the other side of the wall, go down the first pipe before
it says "WELCOME TO WARP ZONE." You will
                      
not come out in 4-1, but in -1. Yes, that's right, -1. World -1 is just
like 2-2, but the pipe at the end takes you back to
                      
the beginning. You cannot beat -1, but it does give you lots of swimming
practice :)
                      
Side note: If you go dowm them before it says "WELCOME TO WARP ZONE," the
second pipe takes you to 5-1, and
                      
the third pipe also takes you to the Minus World.
 
 
                      
Small and Fiery
                      
Being either Super or Fiery Mario, get behind Bowser and let him walk towards
you. Jump, and try to land on the Axe
                      
and Bowser at the same time. You will defeat Bowser and move on as Super
Mario. In the next World, the next
                      
powerup you'll get is a Mushroom, which will make Mario small. Next item
you'll get is a Fire Flower, which will turn you
                      
Fiery, but you will remain small. Note: This will not work in 8-4.
 
 
                      
Thank you dead Mario!
                      
Being small Mario, get behind Bowser and let him walk towards you. Jump,
and try to land on the Axe and Bowser at
                      
the same time. Bowser will hit the lava, as usual. Mario will "die" but
he will angle towards the Mushroom Retainer and
                      
off the bottom of the screen. The Mushroom Retainer thanks you, and you
move on to the next level. Note: This works
                      
in 8-4 also.
 
 
                      
The Magic Koopa Troopa
                      
You may already know that it's possible to stomp a Koopa Paratroopa twice
in mid-air. If your second stomp is when
                      
the Koopa Troopa is 1 or 2 block heighths from the bottom of the screen,
he will go into his shell (duh), but it will be
                      
floating in mid-air! Of course the only way to get the Koopa Troopa 1 or
2 block heighths from the bottom would be to
                      
stomp on him over a pit. For a real challenge, try to double-stomp a Paratroopa
and land on solid ground. The best
                      
place I know of is in 4-3. This is extremely difficult, however. So anyway,
after you land on the platform, the Koopa
                      
Troopa should be in his shell and floating. Wait a while and he'll pop
back out and start walking, while still floating in
                      
mid-air! (I always do this bug in 4-3, but I assume it can be done in similar
levels such as 1-3 or 5-3.)
                      
-- [Found by Deezer]
 
 
                      
Mario Copperfield
                      
If you are Fiery Mario, you can pull off this cool stunt: Before any level
begins (during the "WORLD #-#" screen), press
                      
and hold A and B. When the level begins, use the arrow keys to move Mario...
and he will be "gliding" along the ground
                      
on one foot! Just release A and B and Mario will walk normally again. This
also works when Mario is coming out of
                      
pipes -- just hold A and B as he is emerging from a pipe....
 
 
                      
Get stuck & drown
                      
If you are Super or Fiery Mario, you can pull this off in any water level.
Stop right before the pipe in the water that takes
                      
you out to dry land somewhere. Press and hold Down to duck, then press
A to swim, and then let go of Down. As long
                      
as your feet don't touch down anywhere, you'll notice that Mario's head
goes all the way through to almost the very top
                      
of the blocks! Keep pounding Mario's head on the blocks as you swim above
the exit pipe. Soon he will moonwalk
                      
behind the pipe and will get stuck. The only way to get out of this is
to reset the game, or wait for time to expire.