What are some alternatives?
When comparing PunchLab and Unvanquished, you can also consider the following products
Battlezone - Futuristic VR tank combat in a sci-fi world.
Quake - Quake is a series of first-person shooter video games released by id Software.
Punch Club - Train hard, fight crocodiles and find love.
Unreal Tournament - Unreal is a series of first-person shooter video games developed by Epic Games.
BotBoxer - A first ever robotic punching bag with computer vision
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.