If you keep falling from ropes and you get reach where you wanna go, climb to the top of the rope to make the rope stop shaking and position yourself to where you want to jump. Slide down and jump there.

Do as instructed in the other two cheats, but this time highlight the large medipack and press L1+L2+R1+R2+up together then press triangle to exit the inventory, then re-enter the inventory and you should see all the items and keys for that current level.

but unfortunatly you have to do the same thing for every level.

do the same as instructed in the level skip cheat, but highlight the small medipack and press L1+L2+R1+R2+up at the same time.

If it worked you should have unlimited medipacks at the inventory screen, Press triangle to exit then re-enter again and you should find all weapons with unlimited ammo(unless you haven't collected those weapons yet then they will just be clips with unlimited ammo).

face exactly north(so the red compass needle is facing north), to do this climb on a ledge and face north then hang on the ledge and press select.

highlight load and press L1+L2+R1+R2+ up at the same time and press triangle to exit the inventory and skip a level.