If you haven't beaten the game, the color of the title screen is normally blue. But after you beat the game, the color switches to purple. You can change it back to blue by pressing Up, Up, Down, Down, Left, Right, Left, Right, B, A at the title screen. Input the same code to change it back to purple.
Exodia Draw Glitch
When playing with an Exodia Deck, If your hand contains, for instance, three of the necessary pieces and Graceful Charity, and you activate Graceful Charity, If you get the final two pieces before you have to discard according to Graceful Charity's effect, and you discard Exodia pieces, the animation for an Exodia victory will play, but the match will be considered a Draw. Weird, huh?
Smashing Ground glitch
When you play this card, normally you destroy your opponent's monster with the highest DEF, but if their monster has 0 DEF, it will actually destroy an empty field zone (Which basically means you wasted it...)
Special Duel
Talk with Joey with a time wizard in your deck to unlock a special Duel.
Special Match
Make an Exodia deck your current deck. Go to the card shop. Talk to Grampa and he will ask you to duel against him using an Exodia deck. Both of the lifepoint scores will start at 10. The only way to win is to get all five pieces of Exodia into your hand. Bringing either players' lifepoints to zero will end the duel in a tie.
Swords of Reavealing Light Glitch
When you activate Swords of Revealing light in real life, normally you would flip all face down monsters face up and if they had an effect their effect would still activate. In the video game, when you activate this card, the monsters that are flipped face up and have flip effects are not activated when they should.
Ultimate Offering
You can't activate Ultimate Offering's effect during your opponent's battle phase.
View the ending credits at any time
To do this, you need to beat the game first. Then at any time, press Up, Up, Down, Down, Left, Right, Left, Right, B, A and you'll get to see the credits again.
Wild Nature's Release Glitch
Normally this card increases one selected Beast or Beast-Warrior's ATK by its current DEF, but the game actually gives all your Beast and Beast-Warriors their original DEF added to their ATK.