Clear the game at least once to unlock the following extra options on your options when you start a cleared game:

• Walk/Run - Changes your default movement between running or walking.
• Extra Blood - Less chat, more splat. Self-explanatory.
• Noise Filter - Masks the radio noise if turned off.
• Bloody Footsteps - Travis makes bloody footsteps when moving.
• Torch Projection - Changes the flashlight to emit images of a pentagram, pumpkin, smiloid, soccer ball, etc.