In World 5-2, time your ascent up the vine so that small Mario gets hit with a hammer while he is automatically climbing. When he respawns at the beginning of the level, a vine will grow right in front of him! It'll appear to be invisible (the castle overlaps it), but Mario can still climb it.

To perform this glitch, you'll have to keep a few things in mind. First, when you reach the vine block, make sure you don't go too far to the right, because you'll need to keep the Hammer Brother on-screen. Second of all, Mario will start auto-climbing after his head goes above the fourth leaf from the bottom. Lastly, you'll need to wait for the Hammer Brother to jump and throw a hammer from the Question Block platform.

Two-player variation: If one player performs this glitch, the vine will grow in front of the other player, no matter which level the player starts in. Depending on the background scenery, however, you may not be able to see the vine, and if it's underwater, you won't be able to climb it.

Two-player multiple 1-Ups trick: Both players can work together in "hard mode"—where all Goombas are replaced with Buzzy Beetles—to get one player unlimited 1-Ups. By staying on a well-placed vine and stomping a beetle shell repeatedly without touching the ground, you'll get more and more points with each stomp, and eventually 1-Ups. A good place to try this is in World 1-2; have the player to receive the 1-Ups lose a life at the start of 1-2, then after the other player does the glitch in 5-2, the new vine will grow at the beginning of 1-2 by the two Buzzy Beetles.