The Superball Mario item is another new item in Super Mario Maker 2 that you can unlock during the game. To do this, you will need to have completed a good part of the single player Story Mode and you’ll need to speak with a specific character to get the mission to unlock the Superball Mario item to use in Course Maker as well as the Superball Mario outfit items.
The character that you need to speak with is the Purple Toad, but he isn’t on the map from the very beginning. You’ll need to progress far enough to the point where you rescue Purple Toad and add him to the map. Once you do he will have a few different quests for you to do, one of which is the Spiny Shell Smashers Mission which allows you to access a group of blocks that holds the Superball Power-up.
Once you have Purple Toad, he will be located on the left hand side of the map next to the castle. Talk to him a few times and he’ll have you do jobs, with this quest chain ending with the Spiny Shell Smashers mission to access a group of mystery blocks. Once you complete the mission you will get the item.
What is Superball Mario?
Superball Mario is a different type of power-up item that can be used on the Super Mario Bros. Course Maker. It functions similarly to a fireball, but instead Mario throws a superball instead of a fireball.
Once you’ve completed the quests above you can then unlock this item for use in the Super Mario Bros. Game Style in Course Maker.