Unlockable List:
Win three matches at Beginner class: Expert Mode 
Beat Pete in the Long Drive challenge on Expert Class: Pete 
Beat Daisy in Challenge Mode on Beginner Class: Daisy 
Beat Drake in the Nearest to Pin Challenge on Expert Class: Drake 
Beat Mortimer in a Skins Match at Expert Class: European Golf Course 
Beat Max in Combination Play on Expert Class: Max 
Beat the Mickey Cup to unlock this somewhat unorthodox style of golfing: Midair 
Matchup 
Beat Morty in a Midair Match: Sky Course 
Win at least 3 matches at Expert Class difficulty: Mickey Cup