AstroMenace is a free open source 3D space scroll-shooter for Windows, macOS and Linux. It is arcade style shooter comes with some good quality graphics and game play which really tests games’s hand-eye coordination. In this game you can upgrade your Weapon and space ship.In this game totally 22 unique space ships are available with its unique attributes.
Red Eclipse is a free and open source single player and multiplayer first person arena shooter game built on Cube Engine 2 using SDL and OpenGL. It has six different game modes: Campaign, Deathmatch, Capture the Flag, Defend the Flag, Bomber and Time-Trial. It is available for Windows, Linux/BSD and Mac OSX.Red Eclipse takes influence from a variety of sources in its mechanics and gameplay. Flow, pacing, and level design are akin to Unreal Tournament, while aspects like burning, bleeding, and some weapon behavior have been adopted from Team Fortress 2. It comes with featuring parkour, impulse boosts, and more.
Xonotic is a free fast-paced first-person shooter that works on Windows, OS X and Linux.Xonotic is a direct successor of the Nexuiz project. The game is based off the Darkplaces game engine which is originally a quake modification. Xonotic has incredibly good graphics for an opensource game and is on par with most commercial games from 2006-2007. The gameplay is of course slightly inspired by several other games, but it is essentially a unique mixture of mostly original and different ideas.