Urban Terror is a free, multiplayer, first person tactical shooter video game. Known for its fast-paced gameplay, diverse game modes, and realistic weapons, it emphasizes teamwork, strategy, and player skill over simple run and gun game tactics. Urban Terror is a cross platform game made available for Windows, Mac, and Linux, and can also be run as a portable game direct from a USB drive.
Alien Arena is a free, open source arena first-person shooter for Windows, Linux, and macOS. Built around 1950s-era sci-fi aesthetics, it delivers fast-paced deathmatch gameplay in the style of classic Quake and Unreal Tournament - with 23 levels, a diverse futuristic weapons roster, multiple game modes, and a mutator system that lets you customize each match. It is fully portable and runs directly from a USB flash drive with no installation required.
Quick summary: Install to a folder, copy it to a USB drive, and run crx.exe from the drive on any compatible Windows, Linux, or macOS machine. No installation on the host system. Supports online multiplayer, offline bot matches, and LAN play. Free to download and play.
Nexuiz is a free, open source arena first-person shooter for Windows, Linux, and macOS. Built on the DarkPlaces engine, it delivers fast-paced Quake-style gameplay - strafe jumping, rocket jumping, a varied weapon roster, and multiple multiplayer modes - in a package compact enough to fit on a USB flash drive. The final open source release, Nexuiz 2.5 (2009), remains freely available and runs well on older hardware that modern shooters can no longer support.
Quick summary: Download, extract to a USB drive, and run directly - no installation or admin rights needed. Play online, offline against bots, or on a local LAN. If you want the actively developed successor with modern improvements, see Xonotic.
Warsow is a free and fast paced first person shooter (FPS) game that emphasizes skill based movement and competitive multiplayer action. With its lightweight design, portable install, and cel shaded visuals, it stands out as a unique alternative to traditional military shooters. Fans of classic arena shooters like Xonotic, Quake, and Doom will feel right at home here.
