Monsters Island is a free-to-play adventure game where you must train, duel, and catch your monsters. It's like a real monster-hunting quest! You'll find various creatures on this island, from minor to big. You'll have to train, duel, and catch them all to survive. 

To train, you need to catch a wide variety of creatures. You can do this by using your monster-hunting skills. To duel, you need to fight with other monster hunters. If you win, you'll earn coins; if you lose, you'll be defeated. With this, you can buy new creatures. You can also evolve your monsters by using the coins you've earned. If you're unsatisfied with your current monster, you can choose to duel with a different one.