Best Yugioh game I've ever played !
Graphic and sound are very good for a GBA game.
The best part , of course, is dueling. This game has 2080 cards in total so you can come up with many strategies. Opponents in game are monsters, each opponent has particular theme deck and their AI is good enough to defeat you.
More thing will be unlocked when you win duel, resolve puzzle, limited duel, theme duel or survival duel. It will take much time but it worths. You will be expert if you can defeat 90% or more of the game. Also, at that time, you can duel with yourself which is the most exciting part in game. At 90%, you will unlock "you" who use the same deck like you. At 95%, you will unlock "Copycat" who use one of your saved "recipe" as his deck (you choose the "recipe" for him).
This game maked me come up with many ideas to build new strategies and I was busy all the time with it. And finally, I have found the ultimate deck. Do you want to find your ultimate deck ? Just grab this game ! Have fun !