There's a new update for Operation Extirpate, here's a list of everything thats new:
-Added 'Options' to the menu
-Added 'OK' buttons to windows such as Help, Credits, etc.
-Added HUD
-Added new detection system:
a. Shows player how aware the closest enemy is of him.
b. Takes gunshots, distance from player and grenades into account
-Added execution system:
a. Players can sneak up to enemies facing away from them and enter a phrase into a dialog box. That phrase is then said by the player to the enemy just before you are able to quickly shoot him in the head for an instant kill.
-Helmets that are shot off can now be shot while in the air
-Pressing 'G' now switches between American grenades, and German
-You can now shoot grenades, first shot propels the grenade, the second triggers the explosion.
-Each gun's bullets now vary in distance it travels, so pistols will now travel as far as rifles, etc.
-Cursor image shows whether the bullets of the gun can reach where the mouse is pointed.
-Dead bodies can now be shot, bullet holes do not appear but you can see the body move from the bullets.
-A shotgun was added to the list of weapons that will be created (Winchester Model 1897).

New update for Operation Extirpate:
-Added menu
-Blood now squirts out of bulletholes in enemy's head
-New scenery such as grass
-Added the beginning movie, does not explain much of what the actual story will be, but it sets the player up.

You can see the topic on the WIP section of the Gamemaker Community:
Link

If anyone would like to help with sprites, it would be much appreciated, as I am not very good at making them...

If you download it, please comment or report any bugs found =)