Here is the full list of all 16 Joe 'n Jo achievements.
100% Joe 'n Jo
Collect all Hats
Beat the Game with an Online Friend
Beat the Game
Unlock the Witch Doctor Hat
Unlock the Prince's Hair
Unlock the Orchid Hat
Unlock the Robot helmet
Beat Region 2
Beat Region 1 with an Online Friend
Beat Region 2 with an Online Friend
Beat Region 1
Unlock the Sunglasses
Unlock the Bone Hat
Unlock the Halo
Unlock the Crown