Weapon and ammo cheat:
At anytime during play have Lara step
left, step right, step left then step backwards then fowards,
turn around 3 times then jump backwards with a twist. so that
you are facing the opposite direction. you should have 5000 ammo
and 50 health packs.
Level Skip:
Repeat the above but instead of jumping backwards with
a twist, jump foward with a twist.