Cheat:
When you get a GAME OVER, hold A and press START on the title screen. This will let you continue from the beggining of the world you died in. You only start from the begging of the world. Not the second or third level of that world. 

Fireworks:
Pull the flag when the last digit is 1,3, or 6. THat will make you get fireworks.

Hints:
To enter World Minus 1, go to world 1 level 2 the cave. Make sure your super mario. Go to the pipe at the very end of the level jump onto it and bust the block beside the block thats beside the pipe(sorry its kind of hard to put into words im doing my best) and the one beside the block you just busted (the one on the left)now for the HARD part get on the edge of the tube.( VEEERY close to falling off)now jump to your right while holding b. Try to jump thru the block it is VEEERY hard to do (i hope this cheat gets in this website its SOO complecated.my deepest apologies.) if you make it thru the wall you will start getting pushed thru and you will end up in the warp zone go into the first pipe you see and if you did it right you will be in world -1 which is a pretty stupid never ending water level thats not worth all the trouble anyhow. So dont get discoureged if you cant do it. It's pretty dumb. Okay now for the other cheat go to any castle while youre smallgotothewall beside the ax bowser will chase you and try to squeeze you quikly jump and try to land on bowser and the ax at the same time. Forget it im not giving the suprise away. Enjoy!

 

Access 5-1 from 1-2:
To access this warp, you must be Super or Fiery Mario. Go to the pipe at the end of the level and jump on top of it. Jump up and break the block over top of the part of the pipe farthest left. Then, position Mario on the edge of the pipe, with one foot hanging off the edge. Duck, then jump backward as far right as possible. If done just right, Mario will slide through the pipe and the bricks. Walk over to the warp zone area and enter the middle pipe. This pipe will take you to world 5, level 1. The same area can be accessed from a pipe in the same place in 4-2. However, this is meant to be a warp zone to 5-1, whereas the 1-2 warp to 5-1 is a glitch. After completing the jump trick in levels 1-2, you can also go down either of the other two pipes, both of which will take you to Minus World -1.

 

Blooper Dodge:
If you just walk along the sea floor, Bloopers will never be able to kill you because they are forced back up just before they hit the floor(or you).

 

Continue Game-Play:
After a game is over, go to One Player Mode, then hold A and press Start . The game will resume from the last world played.

 

Level Warp:
To warp to Worlds 2, 3,or 4 during World 1-2, go to the end where the 2 platforms are rising, get on the first platform, and use it to jump onto the highest structure in the middle, then jump on the next rising platform, but this time, when it reaches the top, jump onto the TOP of the level. Walk foward and drop down the small jump, and you can now warp to Worlds 2, 3, or 4 by going down the desired tube, and pressing down.

 

Level Warp to World 6,7 or 8:
To warp to World 6,7 or 8 during World 4-2, go to the place where three blocks are can be seen (where a pipe can also be seen). Jump below the third block where you can reveal a secret block but be careful on jumping below the 1st block because you can't break it thus going to the secret warp world unless you are a small Mario. Then step on to it and break the 2nd and the 3rd block. After you have done this, go down, then jump again below the second block now (it should have been broken now). The position of the two revealed blocks must be a stair from right to left. Anyway, step on to the 2nd block then braek the 1st block and there you can see the vine going up. Climb until you reach the day light again. Get some coins if you wish and you can now see three pipes like in the secret warp Worlds 2,3 and 4. Go down your desired pipe.

 

Negative World:
Go to World 1-2. At the pipe that leads to the flag, break two blocks so there's one at the end touching the pipe. Now duck and jump backward toward the brick (don't break it!). You should go through the wall and pipe into a warp zone. Jump down the first pipe you see and you will be in the Negative World (-1)!

 

Shoot fireballs as small Mario:
Go to either 1-4, 2-4,3-4, etc. and get to Bowswer. Make sure you are Big Mario and try to jump over Bowser or run under him. Stand near the Axe and Bowser will start to walk towards you. As he gets near you, jump high, and touch Bowser and the Axe at the same time. If you do it correctly, you will hear the sound as if you were to shrink, but you will just flash and stay big. Go to the next stage, and get a Mushroom. (Yes, there will be a Mushroom instead of a Fire Flower.) When you touch the Mushroom, you will shrink. Then get a Fire Flower, and you'll have Fire Power as small Mario. (Note: after you do the Bowser/Axe trick, enemies that touch you will be able to kill you when you are Big Mario. When they touch you while you are small Mario after getting the Mushroom or Fire Flower, you will turn back into Big Mario.)

 

Unlimited 1-Ups:
Get to world 3-1, and become Super Mario. At the end of the level(the staircase before the end flag) you will see two turtles coming down the stairs, jump over the first one and then jump on the second one. It should hit the star and bounce back, from here jump on it and keep yourself up, after a certain number of bounces without hitting the ground, each consecutive bounce will get you a 1-up. Get as many as you want but be warned, if you get over 100 you will get a Game Over.

 

Warp to World 5:
Well this secret is so easy. At the very end place of world 4-2 (where you can see the pipe going to the flag) jump on the long pipe and break the brick above it and go through the end and you can see the pipe going to the World 5.

 

Multiple Game Genie Codes:
Keep in mind that these codes will only work if entered correctly with the NES game genie cheat cartridge. They are very hard to find. I will give you codes to enter ito the game genie to make your Mario playing time more fun.

 

~One Player Mode Only~
Start On World 8: enter YSAOPE YEAOZA YEAPYA as a code.
Running Super Jump: enter TPZLTG as a code. (note: this means you will jump higher than the screen shows when you are running regular speed, so you go higher.)

 

~Two Player Mode Only~
Infinite Lives: enter SXIOPO as a code. (both Mario and Luigi will have infinite lives.)

Tweak Music:
Using a Game Genie, enter PPPPPP as a code. This will cause the background music to change. Overland levels play the underground level's music, undergound levels play a short intro then don't have music and castles play part of the overland music in a loop.