Bugs:Super Mario World (NES)

This page details bugs of Super Mario World (NES).

Counting Errors

Due to a programming error, the game requires you have 101 coins to get a 1-Up, rather than the standard 100. This isn't too big of an issue, however, since your current coin amount carries over between levels.

On a similar note, collecting five Dragon Coins in a level is supposed to give you a 1-Up, as in the SNES original, but the aforementioned error means the game checks if you have more than five Dragon Coins rather than at least five. Since Dragon Coins do not carry over between levels (consistent with the original), there are never more than five in any given level, and no points are awarded for collecting them, the end result is that they're entirely pointless in this version.

Carrying Air

Holding a Koopa shell and running into one of the player's fireballs with it will destroy the shell the player is carrying but leave the player in a carrying position. The player will be locked in this state until exiting the level.

Level Advancement Cancel

Entering the level the player is on during the brief frame window before they move to the next will cancel the advancement to the next level.

Yoshi in Castle

Entering any castle with Yoshi after already reaching a checkpoint will allow you to use Yoshi in that castle.

Yoshi Spit Cloning

Repeatedly pressing B while spitting out any object, such as fireballs or springboards with Yoshi will cause him to spit out multiple of said object. This can severely corrupt or even crash the game if too many are spawned.

Pause Glitch

Pausing the game on the same frame an event is triggered will cause the music to cut out until the player is able to unpause again. This is because the flag that determines if the game is paused is only checked when an event isn't occurring, meaning that only the secondary effects of the game being paused, such as the music being muted, will take place. This can have noticeable effects on level exit events, causing the music on the map to be muted until the player enters a level and unpauses the game.

2-Player Yoshi House Glitch

Entering a Yoshi House as Luigi while Mario has any powerup will cause the game to load a flooded, glitchy level in place of Yoshi's House. This is caused by both Mario's powerup state and Luigi's checkpoint flag for Yoshi's House being stored at memory address $06DA. If Mario is in any powerup state except small (which is 00), the checkpoint flag will be set, and invalid level settings will be used when Luigi enters Yoshi's House.

Select Buffering

Repeatedly pressing Select while in a level while the reserve item box is either empty or unusable will cause the game to repeatedly pause for a brief period of time to check the item box. This can be used to slow the game down slightly and stall animations.

Springboard/P-Switch Sliding

Repeatedly releasing and grabbing either a P-Switch or springboard will cause it to slide in the player's direction. During this state, its hitbox stops functioning and it will slide in the opposite direction of any wall it hits.