Tomb Raider - Unfinished Business cheats and cheat codes for PC

Completion bonuses:
Finish the game and load any previously saved level. Game will start 
with all weapons, infinite ammunition and  more opponents. 

Get all weapons
Have Lara walk one step forward (hold [Shift]), one step back 
(hold [Shift]), rotate in 3 full counter-clockwise circles 
(hold [Shift]), and jump back (hold [Alt]).

Skip any level
Have Lara walk one step forward (hold [Shift]), one step back 
(hold [Shift]), rotate in 3 full counter-clockwise circles 
(hold [Shift]), and jump forward (hold [Alt]).

Roll easily:
Instead of pressing (End) press the (Up) + (Down)