King Arthur´s Gold (Steam key/Region free).

http://store.steampowered.com/app/219830/
If you like total freedom in the way you conquer the enemy this is the ultimate war game for you. Build freeform constructions as a medieval Builder, fight in sword duels as a Knight or snipe with your bow as an Archer. KAG blends the cooperative aspects of Lost Vikings, mashes them with the full destructibility of Worms and the visual style and action of Metal Slug, brought to you by the creators of Soldat.

Build Defenses With Freeform Building
Destroy the enemy castles with physics and explosives
Freedom to move by land, water, dig tunnels or fly in the air
Use the environment to burn or drown enemies
Interact with a living animal and plant world
Drive siege machines with your teammates
Fight with 32 unpredictable humans in multiplayer
Freely change to one of 3 distinct classes
Singleplayer, cooperative and competitive game modes
Customize with 60+ unique heads
Create your own adventure with community created mods & scripts