In "Yu-Gi-Oh! Monster Capsule GB," you take on the role of a monster trainer who needs to collect and train monsters from various cards that you acquire by playing and winning battles. These monsters are used in strategic turn-based combat, where skillful tactics are key to defeating opponents. You can collect monsters from cards and train them to enhance their combat abilities. The game focuses on strategic combat, with each monster possessing unique skills and abilities that can be utilized in battle. Although it’s not a traditional card game, cards are still a crucial element for acquiring monsters and equipment.