Enter one of the following codes at the computer in the Batcave to unlock the corresponding option at the "Extras" menu. If you entered the code correctly, the name of the cheat will appear.

Result - Code
Extra hearts - ML3KHP
Unknown - XWP645
Unknown - DDP967
Unknown - XVK541
Unknown - RDT637
Unknown - NJL412

Bonus characters. Enter one of the following codes at the computer in the Batcave to unlock the corresponding character:

Character - Code
Bruce Wayne - BDJ327
S.W.A.T. - HTF114
Tropical Joker - CCB199
Yeti - NJL412