In order to use cheat codes, players typically need to enter hidden passwords or hit gamepad keys in a specific order. Less frequent activation techniques include gathering up things in a specific sequence, making other counterintuitive actions, gripping keys or buttons while dying, inputting specific high score names, and more. A development interface may be available in some titles, allowing players to change game settings.
This gives you nothing but the codes/passwords you need. You cheaters. Guide to Hacking with Tenma Codes/Passwords