You must have the cheats unlocked in your Extras menu before they work. (unlock the cheats by gathering all the secret items)

Code Effect

Hold Backspace and press 7 Bulletproof Lara
Hold Backspace and press 3 Infinate Assault Rifle Ammo
Hold Backspace and press 4 Infinate Grenade Launcher Ammo
Hold Backspace and press 5 Infinate Shotgun Ammo
Hold Backspace and press 6 Infinate SMG Ammo
Hold Backspace and press 8 One Shot Kill
Hold Backspace and press 2 Show Enemy Health
Hold Backspace and press 1 Textureless Mode
Hold Backspace and press 9 Wield Excalibur
Hold Backspace and press 0 Wield Soul Reaver

Unlockables

Character Profiles - By collecting the Bronze Reward items you can obtain character profiles.

Alister Fletcher 90% Bronze
Amanda Evert 70% Bronze
Anaya Imanu 30% Bronze

James W. Rutland 50% Bronze

Lara Croft 10% Bronze

Shogo Takamoto 40% Bronze

Toru Nishiruma 40% Bronze

Unknown Entity 100% Bronze

Winston Smith 80% Bronze

Zip 20% Bronze

Lara's Many Outfits - To collect Lara's wardrobe of outfits, you need to collect and conquer special circumstances.

Amanda Ritual Outfit Complete Ghana Time Trial
Amanda Winter Outfit Complete Kazhkastan Time Trial

Biker Finish England Level
Biker without Jacket 100% Silver and Gold in England
Black Bikini (Croft Manor) 100% Bronze, Silver and Gold in all Levels, beat Time Trials and Complete the game
Black Legend 100% Silver in Croft Manor
Blue Legend 100% Silver in Peru

Catsuit 100% Gold in Japan
Classic outfit 100% Gold in Peru
Cream Suit 100% Silver and Gold in Croft Manor

Goth Complete England Time Trial
Gray Classic 100% Gold in Ghana
Green Sport Outfit Complete Bolivia Time Trial

Lace Shirt Goth Complete Japan Time Trial
Legend Unlockable from the start of the game

Pink Legend 100% Silver in Ghana
Pink Winter Complete Nepal Time Trial
Pink Winter, No coat Complete Peru Time Trial

Red Jacket Biker 100% Silver in England
Ripped Evening dress Finish Japan Level
Ripped Red Evening Dress 100% Silver in Japan

Snowsuit 100% Gold in Nepal
Special Forces 100% Gold in Kazakhstan
Special Forces (Urban) 100% Gold in England
Sport Outfit 100% Gold in Bolivia
Suit 100% Gold in Croft Manor

Union Jack Legend 100% Silver in Bolivia

White Bikini (Croft Manor) Complete all Time Trials and beat the game
Winer, Orange No coat 100% Silver in Kazhkstan
Winter outift Finish Kazakhstan Level
Winter, No coat Finish Kazkhstan Level
Winter, Orange 100% Silver in Nepal

Location Concepts - By collecting all the Bronze rewards in Levels, you get the location concept. This includes many different sketches of the level's creaction.

Bolivia 100% Bronze in Bolivia
England 100% Bronze in England
Ghana 100% Bronze in Ghana
Japan 100% Bronze in Japan
Kazakhstan 100% Bronze in Kazakhstan
Nepal 100% Bronze in Nepal
Peru 100% Bronze in Peru
Special 100% Bronze in Croft Manor

Pistol Upgrades - To get these Pistol upgrades you need to obtain a certain amount of Reward items in levels

Extra damage 75% Bronze and Silver

Increased Accuracy 50% Bronze and Silver
Increased magazine size (40 bullets) 25% Bronze and Silver

To obtain cheats in the game, you must complete certain Time Trials in Levels (mins:sec)

Bulletproof Lara Complete England in less than 27:00

Draw Enemy Health Complete Bolivia in less than 12:30

Infinite Assault Rifle Ammo Complete Japan in less than 12:15
Infinite Grenade Launcher ammo Complete Kazakhstan in less than 27:10
Infinite Shotgun ammo Complete Ghana in less than 20:00
Infinite SMG ammo Complete Peru in less than 21:30

One Shot kill Complete Bolivia Redux in less than 4:15

Wield Excalibur Complete Nepal in less than 13:40
Wield Soul Reaver Complete Game and all time trials