Upgrade Weapons 
     Enter  the  Konami code in the pause menu to upgrade your weapons
fully.  Note  that  this code can only be used once per life (doing it
again  will  kill  you) and that it can only be used in Normal or Hard
mode (easy gives you full upgrades automatically)

Cheat:                                                 Effect
Up, Up, Down, Down, Left, Right Left, Right, B, A,     Start Upgrade 
                                                       weapons fully
                                                       
        
Challenge Mode Unlockables
                                                       
Unlockable:              How to Unlock:
Probotector              Beat 12 challenges in Challenge Mode 
Contra (NES)             Beat 4 challenges in Challenge Mode 
Super C (NES)            Beat 8 challenges in Challenge Mode 
Sheena Etranzi           Beat 28 challenges in Challenge Mode 

Challenge Mode 
     Complete  the  game  on  any difficulty to unlock Challenge Mode.
This includes Easy.