Cheats

All Weapons
During play, hold the WALK button and sidestep Left, then Right, then Left, then step Backwards, then step Forward. Then turn Lara around three times in any direction, then jump backward and while in the air press the ROLL button.

Exploding Lara
During play, hold the WALK button and sidestep Left, then Right, then Left, then step Forward, then step Backwards. Then turn Lara around three times in any direction, then jump forward and while in the air press the ROLL button.

Get Rid of The Butler
Walk into the kitchen and open the freezer, go inside and wait for the butler to arrive. Once he comes in jump over him and close the door behind you.

Infinite Flares
During play, press L2, L2, L2, L2. When you bring up your inventory you won't see the flares, but you have an unlimited supply. Press Triangle + L2 while playing to use them.

Level Skip
During play, hold the WALK button and sidestep Left, then right, then left, then step backward, then forward. Then turn Lara around three times in any direction, then jump forward and while in the air press the ROLL button.

Secret Room in Lara's House
When you explore the outside of the house go to the front door and open it. Walk straight in and look at the two halls on each side of the clock. Leave from the door you just opened and go to your left and head into the maze. Go left always in the maze unless your only option is to go right. When you get to the back of the maze you will see a brick wall, look down the hall and you will see two openings. Take the first opening to the right and fall into the hole. Then go to the end of the hall and jump out, push the button on the wall and you will see a cinema of the door opening back in the house. The door is timed, so you must be fast. Go back the way you came in, jump out of the hole and go left. Then keep following the maze turning right everytime unless you have to turn left. Exit the maze at the end and run back into the house and through the door. It leads to the basement below, where you'll you will see several chests and windows on each side. It looks like a huge statue is on the right.