Killing Floor/Controls

Weapon/Equipment selection
All weapons and equipment are accessed via just five buttons:
 * Equipment key: cycles syringe and welder
 * Melee weapon key: cycles chainsaw, katana, axe, machete, knife
 * Pistol key: cycles handcannons and 9mm
 * Main weapon key: cycles lever action, bullpup, Ak47, and shotgun
 * Special weapon key: cycles medic gun, hunting shotgun, auto-shotgun, SCAR, crossbow, M14, flamethrower, grenade launchers, and pipebomb

There are also some quick access keys:
 * Flashlight key: usually pulls out your 9mm with the light on
 * Self-heal key: pulls out and immediately uses the syringe on yourself. Afterwords it restores your original weapon

Weapon use

 * Primary fire
 * Use iron-sights
 * Alternate fire (either a significantly more powerful attack, a semi/auto mode selector, or a laser sight toggle)

Movement
FPS game standard WASD, jump, and crouch keys. Very useful but seldom seen in games out of the box is a toggle crouch key. Use it.

Other keys

 * Drop money
 * Drop weapon
 * Reload
 * Throw grenade
 * Enable/disable flashlight
 * VOIP (this is very well implemented in KF since it actually cuts out the background music when you talk)
 * Canned speech menu