Mario & Luigi: Bowser's Inside Story Action Replay Codes

Debug Menu/Room

Hold B when going somewhere inside Bowser and you'll go into a room with 4 ! Blocks. Do not use with Bowser or Mario & Luigi when they're outside Bowser.
Here are the functions.
Lower-Left Block
0 - Shake animation
1 - 'Mario lands in Bowser's Insides' cutscene in the first room in the Trash Pit. Mario only, you cannot switch to Bowser when activated. Luigi is trapped a few rooms below.
2 - Brings you right to Luigi in the Trash Pit.
3 - Brings you to the elevator room in the Trash Pit.
4 - Brings you to the room where you get your first Green Shell Attack Part.
5 - Brings you to the room with the last Green Shell Attack Part.
6 - Brings you into the first hammer battle room.
7 and up - Brings you into the Bowser Room Select Screen


Upper-Left Block
0 - Starts the intro cutscene.
1 - Brings you to the Peach's Castle, where you're greeted by a Toad.
2 - Shows the backrground used for the first Bowser Battle on which you can freely move around
3 - Starts the cutscene which happens when you beat Bowser at the start of the game
4 and up - Brings you to the Bowser Room Select Screen


Upper-Right Block
0 - Brings you to Pump Works Gate Room
1 - Brings you into the Fire Pipe Room
2 - Crashes
3 - Brings you into the Bone Room where you fight Durmite for the first time
4 - Brings you into the room where Toadbert was originally trapped
5 - Brings you into the second Flab Zone room
6 - Brings you into the first Nutsoglobin Room
7 - Brings you into the third room in Flab Zone after the E'erlasting Wonder Treasure room
8 - Brings you into Spin Bros. Room in the Flab Zone
9 - Same as 8, but in a different spot
10 - Brings you into the Alpha Cretin boss room
11 - Same as 10, but in a different spot
12 - Brings you into the first Fat Flab Zone room
13 - Mushroom Flab Zone Room
14 - Some room in Energy Hold obscured by a purple beam of light. If you jump, you'll hit a Save Block, so it's probably the first room.
15-26 - Some room in Energy Hold obscured by a purple beam of light.
28 - Lumbar Nook
29-34- Toad Plaza with the Camera weirdly offcenter