These cards have no artwork, crash the game when played, or show as "???". But for completionists:
Have a code we missed? Share your own Yu-Gi-Oh! Forbidden Memories Gameshark discoveries in the comments below (or on the Yu-Gi-Oh! subreddit’s cheat thread). Yu-gi-oh Forbidden Memories Gameshark Codes
Here are some working Gameshark codes for Yu-Gi-Oh! Forbidden Memories: These cards have no artwork, crash the game
Instantly reduces the opponent's Life Points to 0 as soon as the duel begins. : 801D07D0 0000 These cards have no artwork