1-When swimming as Mini Mario in the water, he will go to the up direction for a few seconds and then goes to the bottom direction for a few seconds(fixed).
2-When you enter a level from the world map while you are Mini Mario, you can't save the power-up in the player's item box(not fixed).
3-If the player got a Shell Power-up and tries spinning with his shell, he can't get in and break the blocks while a normal shell can like in the image below(not fixed):

