Hello!

"I'm not going to shoot you between the eyes...I'm going to shoot you between the balls!"

Bennett, from Commando

The game gives you bonus damage for head shots, like any other FPS. However, you also get the same effect if you shoot your enemies in the crotch.

Edit: formatting.

Edit 2: Some of the enemies have extra amour on them. Shooting their family jewels is the ideal target when fighting them.

It's a shame there is no "Like" button on GOG forums.