Super Mario Bros. 2 is a US remake of the Japanese Game Doki Doki Panic where Mario, Luigi, and the others must defeat the evil Wart.
In 1-1, there is a door leading to a Cave and the exit of the cave is right above. If the player hops on a Tweeter and does a powered up crouch jump when it jumps, they will get up to the cliff above and skip the Cave.
First, get a Potion and throw it on a Vine, now the door cannot entered.
Cyberspace Warp Error Edit
First, find a potion and a warp you can go down. Throw the potion and enter Cyberspace and go down the Pipe.