Enter the following codes during gameplay (preferably when you are not near enemies) to enable the corresponding effect. The Bulletproof Lara, Draw Enemy Health and One Shot Kill codes will only work if the game has not been patched with the 'Title Update 2'. If you enter a code correctly you will hear a confirmation sound.
Hold LT and press A, RT, Y, RT, X, LB.
Draw Enemy Health
Hold LT and press X, B, A, LB, RT, Y.
One Shot Kill
Hold LT and press Y, A, Y, X, LB, B.
Hold LT and press Y, click the Left Analog-stick, press B, RB, X.
Hold LT and press X, Y, RB, A, B, LB, X. Then hold RT and press LB during gameplay to emit a nuclear wave.
Hold LT and press A, RB, LB, RT, X, Y. Execute the swim faster move while swimming to activate the code.
Stage Section Clear
Hold LT and press RB, Y, A(2), B, RB.