What are they and how do you get in you ask?? Well Secretnotes will tell you!!
First you have to have the game in your backpack. (To do this play at the game wagon in Presto grove) After you have it in your backpack click on the game you want to play and click the SOLO option for points. There will be a bar at the top, everytime you beat the game it will fill slightly. When it fills completely it will unlock a BOSS MISSION. Here is where each boss is located:
Skytown Skatepark: Professor Plumpox Lab
Wildwood Glen : Rat Wraith Lair
Tanglevine Jungle : Grool Grubnibblers Lair
There you get to Choose one free item!!