From CloudModding MM Wiki

To use the debug functions, it is necessary to have Controller 2 plugged in when you start the game. Otherwise, all the debugging features will be disabled, and the game will run noticeably slower.

Input Display

Small, coloured squares at the bottom right of the screen show which buttons you are pressing.

Access Map Select

Press L + R + Z on Controller 1 to open Map Select from anywhere in the game.

Free Movement Mode

This mode allows Link to move about at will, floating through the air, submerging himself beneath the ground, and passing through obstacles. All commands are for Controller 1.

D-Up: Activates and deactivates free movement mode C Buttons: Moves Link forwards, backwards, and sideways A: Moves Link down B: Moves Link up

Switch Forms

Pressing L + D-Down on Controller 1 switches Link's current form. The order is Link --> Fierce Deity Link --> Goron --> Zora --> Deku.

Inventory Debug

At the pause menu, press L on Controller 1 to open the inventory debugger.

Memory Viewer

Various button combinations on Controller 1 can be used to access the memory viewer.

Camera Debug

Press Start on Controller 3 to enable camera debug.

Environmental Tools

Press Start on Controller 4 to access the environmental tools.