At the password screen enter 1HHHHH2. After you enter it you will have 16 hearts and be on Shreder's level
On the last spot on the password you can always put 2 on the end no matter what password you got and get 2 continues.
Level - PasswordBefore Scratch - 1000002After Scratch - 2100002After Card 1 - 4110102Before Dirtbag - 1111102After Dirtbag - 2311102After Raphael - 3311302After Card 2 - 4331302Before Triceraton - 1311302After Triceraton - 2711302After Donatello - 3711702After Card 3 - 4773702Before Scale Tail - 1777702After Scale Tail - 2H77702After Splinter - 3H77HO2After Card 4 - 4HH7HO2Before Shredder - 1HHHH02