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When you start a new game, you can to choose to use Isaac as the main character's name, or a new name that you choose. You can also enter names for Garet, Ivan, Mia, Felix, Jenna and Sheba.

To change Garet, Ivan, and Mia's names, press three times in a row and a chime will play. The code to change Felix, Jenna and Sheba's names is a little more complicated. Enter the following code: , , , , , , , , , , , , , . You'll hear a chime after this code to let you know that it was entered correctly.