Kid mode (Jojo's Bizzare Adventure):
Defeat more than fifteen characters in survival mode to unlock kid mode, which allows
the characters to appear as kids. 

Play as Young Joseph (Jojo's Bizzare Adventure): 
Successfully complete arcade mode as Joseph. 

Play as Evil Dio (Jojo's Bizzare Adventure): 
Successfully complete arcade mode with Dio. 

Play as Evil Dio (Heritage For The Future): 
Successfully complete challenge mode as Dio to unlock Evil Dio.

Play as Young Joseph (Heritage For The Future):
Successfully complete challenge mode with Joseph. 

Play as Dio (Jojo's Bizzare Adventure): 
Successfully complete arcade mode with Jotaro.