Continue game play:
After a game is over, go to one player mode, then hold A and press Start . The game will resume at the last world played.

Hint: Extra lives:
Play until World 3-1, then go to the stairs just before the flagpole. Two turtles will come down the stairs. Kill the first one and walk to the first block. Get right next to the block and wait for the second turtle. As it gets on the first block, jump on its head. If done correctly the turtle should be sitting on the first block with it head in its shell. Then, jump on the edge of the shell. Do this repeatedly to get extra lives. If this trick fails, return to the pit and fall, then try again.

On World 1-1, when you jump over all of the tubes, after the last one (where you have to jump over the first ditch), go to the back of the green hill in the background and jump. A box will appear with an extra life.

Hint: Warp zones:
In World 1-2, you can get to a warp zone by getting "on top" of the level. When the platforms move up, jump on the high row of blocks. Then just run across until you fall into a warp zone. You can now go into any World up to 4.

In World 4-2 you can get to a warp zone by getting "on top" of the level. When the platforms move up, jump on the high row of blocks. Then, just run across until you fall into a warp zone. You can now go to World 5-1.

Glitch: Missing Mario:
Go to any Boss level, except for the final level. Make sure Mario is small when reaching the Boss. Jump on the small ax object so you hit Koopa (Boss) and the ax at the same instant. You will die but can continue on. Toad will talk as if you were there then the game will continue on without you losing a life.

Glitch: Small Mario with fire ability:
Go to any Boss level, except for the final level. Make sure Mario has the fire ability when reaching the Boss. Jump on the small ax object so you hit Koopa (Boss) and the ax at the same instant. You will die but can continue on. Mario will be small but retain his fire abilities.

Glitch: Falling King Koopa:
When facing King Koopa, if you have the fireball and kill him with it, he will fall from the bridge in three variations:

As a green Koopa shell.
As a gray Koopa shell.
As a gray Goomba.