Way too much on the screen at once. Visual clutter + no highlights to show what's clickable = utter confusion! Maybe it's just not my type of game, although I did love to play yugioh as a kid. Also the tutorial would have benefited from having the player actually click on buttons they'd be clicking on in-game, rather than just clicking next and being barraged by a procession of text. You've probably seen this in a lot of games, and I know it's more difficult to implement, but after the tutorial I really had no idea how the game worked and I just didn't feel like redoing it was worth the effort. And just so you know it's not just that I'm lazy or anything. But from the complexity of the rest of the game, I think you could probably do the tutorial the way i described.