Soldat 2 is coming to Steam Early Access this quarter. In preparation here's a free demo! 

More info about Soldat 2:

A direct successor to the 2D multiplayer shooter Soldat which took the Internet and LAN parties by storm in the early 2000's.

Soldat 2 aims at recreating the basic Soldat gameplay experience with fresh and enhanced content. Customization and modding will be a core feature with procedurally generated levels, custom game rules and modes, weapons, vehicles, structures and a battle simulator sandbox. Soldat 2 strives to become a powerful platform for custom created content, mods and other Soldat-like games

Early Access Features:

• online multiplayer (with dedicated servers)
• procedurally generated and designed levels
• famous from its predecessor physics-based movement
• low-poly style for easy mod creation
• realistic weapons and military equipment
• ragdoll physics and over the top violence
• custom battle sandbox

Upcoming:

• level editor + generator
• full mod support
• explosives + level destruction
• more character customizations
• more weapons and equipment
• more levels and game modes
• classes, vehicles and other experimental features

Developed by one man,
the original creator of Soldat, King Arthur's Gold and producer of Butcher
Michal 'MM' Marcinkowski.