Very good game for its release time.It has most of the important cards ever released before this game is out.
As usual this is the best Yu-Gi-Oh! game to be released in GBA or NDS.Sorry for this,but despite for what i have written above,this game is still missing some good cards,such as Zombie Master and Bazoo the Soul Eater.But this game is still worth it.Some people keep complaining that the last game, World Championship 2006 has all the cards ever made until its release.I hope you do not look bad on this game because of that reason.The old cards are pretty much useless.They are a bunch of vanilla cards,no effects,and low attack points.Some effect monster cards are terrible and i believe you would not put them into your deck even if they are included.While this game,it includes all Elemental Hero cards ever made before its release, which is very COOL!
2008 cards are enough to give you a lot of funs.These cards include Crystal Beast monsters,Volcanic monsters,Cloudian monsters,and many other themes.This game provides you 120 slots for deck recipes, and you can construct many kinds of decks in this game.In World Championship 2006,you have all cards ever made in the past but not the latest released themes.So i think this game is better.
To recall back,the first Yu-Gi-Oh! game in NDS is the Nightmare Troubadour.It has 1000+ cards.Sprit Caller has 1400+,and World Championship 2007 has 1600+.This game has 2000+ and has all cards which the last games have.So this should be worth it.
The difficulties in this game is not in the duel,but in unlocking more funs.You need to do many things to unlock new worlds,new players,new card packs,...But these are the things that make this game fun.Although the Starter Deck is the worst i have ever seen,it is better than having all cards from the beginning of the game,and play with too competitive decks through out the game.You will lose all the funs very fast.
There are 13 tiers in world championship mode,which means 13x6.So,there are 78 players you can duel against.In duel world,there are still duel spirits ready to duel you.Structure Duel in the first world is pretty fun as well!
And do not forget that is Wi-Fi for this game.You can duel the world,download new cards everyday(which never help me so much,but may be useful if you just start the game),new duelists in the leaderboard(although it is a house for some hackers),new Duel Puzzles(very fun!),and new Banlist.The limit for duelist download is 18 tiers(18x6=108 duelists).
If you love Spirit Caller, 2 musics from that game make a return in this game.
Sorry for the long review,hope it helps you.I really encourage you to buy this game.I do not regret buying this game,and enjoyed it a lot.I have played it for 400 hours(in game time).It really worth it,believe me!
Please have fun with this game,good luck on unlocking everything.It takes around 200 hours to unlock everything without cheating(as you unlock Yami Malik after playing for 200 hours),and the overall score for this game is,...I give 8.5 (too high seems a bit buyer)