Basics as Player PC

Use "W" "A"   "S"   "D" to move around

Use mouse to look around and change view

Use "E" to open or close doors or activate activatable things like open locks or cut wires or ETC

Hold "E" free yourself from beartraps

Hold shift to run ( limited )

Use "C" to crawl or stand up

Use Left-Click to shoot at granny by shotgun or other weapone if you have one.

Anything Else ?