Wow. I was quite amazed when I first tried this game. It a VERY slow progression through the story. If you have beaten The Sacred Cards, then you'll understand what I mean. When you beat a regular duelist, your capacity only increases by 1, not 3 and when you beat a special duelist deck like mako or weevil, your capacity wont increase by 10, again 1. So its very hard to put a good card in your deck. Also you get a LOT less money from winning. Beating Tristan only gives 1 Domino (prize money for beating duelist), all of his cards suck, are weak, and don't sell for much. Yugi and Joey only give 100 domino, but give somewhat good antes ranging from 150 to 300. However, the cards in the shop are VERY expensive. Also, the duelist level goes up by 1 every few duels, not every single duel won. Also what makes this really, really time consuming is that the cursor moves around the field every turn to check for cards that have continuous effects and wastes so much time. It takes me about 1 full minute to beat tristan with my very powerful warrior deck and gods. I stayed away from having cards like machine king or slifer around because their effects stall. So this game is more boring and longer. It took me months to beat the game, but its simple gameplay was addicting to me. The graphics aren't good. They cards in a duel while just looking at the 5 cards to choose from still look bad, but will look better when looking at details. But another thing I hate is that the current Life points you have after beating your last opponent is the amount of Life points you have next duel. However you can not start with over 8000 life points, so don't think about starting with millions. The actual ritual monsters like blue ultimate or Cosmo queen all cost 999 to add in your deck. Worst is that you need to go back to your house and only your house to restore lost life points. At the end, the evil antagonists have about 20000 life points while you start with only 8000. If you're addicted to a good challenge, then play this game, but otherwise this game takes forever. I beat it, but that's because I had a lot of free time with nothing to do.

There is this site I used to find a good deck and to help me progress.
go to Google and search the name of the game and put "cheats" after the name. The site is gamewinners.com. This has the card codes to input in the shop, good cards to include in your deck, and hints about the game play.

To help those playing, buy the cards Doron x3, Dark Flare Night, Newdoria, Ancient Lamp x3, Cocoon of Evolution, Pot of Greed, Winged Dragon of Ra [(Phoenix mode)find the game site I mentioned to learn to get the Phoenix mode, not the original battle mode)
Trust me, the cards I listed are very good to include
to your deck.