Digital Paint: Paintball 2 is described as 'Paintball game that started out as a mod for quake 2 but then took on a life of its own as an open source fps game with a global player and clan management system' and is a first-person shooter in the games category. There are more than 25 games similar to Digital Paint: Paintball 2 for a variety of platforms, including Windows, Linux, Mac, Flathub and Steam apps. The best Digital Paint: Paintball 2 alternative is Xonotic, which is both free and Open Source. Other Digital Paint: Paintball 2 like games are Counter-Strike, Unreal Tournament, Quake and AssaultCube.
A truly free and open source multiplayer shooter, no strings attached. Have casual deathmatch matches on various scenarios. Build your own levels with the ingame editor and assets that come with the game, or just play around and use it as a sandbox.
Germany
EU
Warface is a contemporary MMO first person shooter with millions of fans around the world. It offers intense PvP modes, compelling PvE missions and raids that you can challenge with four diverse classes and a colossal customizable arsenal.
Russia
The website linked is not real page, just moddb page. Wikipedia says all official sites have been closed.
United States
Shoot'Em Down and Shoot'Em Down II are two first person shooter games adjusted to the death-match style. Four player teams fight against 4-6 player opposing teams.
Wrack: Exoverse is the follow-up to the 2014 first-person shooter Wrack. It was a very fast-paced, arcade-style game with heavy influences from classic shooters like Doom and Quake.
United States
Syphon Filter is a third-person shooter video game series, developed by Bend Studio, known for its blend of action, stealth, and puzzle-solving elements, following the protagonist Gabe Logan's missions to rid the world of the Syphon Filter virus.
United States
Battle through an onslaught of mystical backwater cultists, possessed militants & even darker forces as you attempt to discover just what lurks beneath the Earth in this retro FPS inspired by the '90s legends.
United States
HateArena is a (very) fast-paced multiplayer and single-player arena shooter. Wall-jumping, shotgun-boosting arena combat built on the Cube engine.
United Kingdom
