The following are known Action Replay Codes for Mario is Missing! on Super Nintendo (SNES).
These codes are for the U.S. version of the game.

  1. Use Computer To View Pamphlets On Any Artifact
    80B5DF80
    Note: No checks appear on computer.
  2. Always Get Yoshi After Using Globulator
    80F80101
  3. Pick Up One Artifact And Get All Three
    80B4FFA9
    80B500FF
    80B501EA
  4. Talk To Someone Once To Learn All They Know
    80B50CA9
    80B50DFF
    80B50EEA
    Note: All 4 checks appear on computer for that person.
  5. Use Computer To Access Any Facts Except Pamphlets
    80B60B80
    80B64D00
    80B67800
    Note: No checks appear on computer.