To unlock more mini-games in the rec room, catch a rabbit with the character you want more mini-games with. For example, catch a rabbit with Mario to unlock a Mario mini-game. Additionally, after you have been in Princess Toadstool's room with the big dresser and all the drawers, go outside in the front yard of the castle. You will need to be playing with Yoshi. You will see three rabbits grouped up together. If you go near them, they will run away very fast. Run after them and catch them with your tongue. The rabbit will plead to let it out. You will automatically spit it out. After it complains about you about almost swallowing it, it will give you a key to the drawers, which will unlock more mini games in the rec room for Yoshi. You will get three keys, because there are three rabbits.