Teeworlds is a free online multiplayer game, available for all major operating systems. Battle with up to 16 players in a variety of game modes, including Team Deathmatch and Capture The Flag. You can even design your own maps!
This is made from the official source of the game without any changes but as I am not part of the developers community I released it as unofficial.
See here for the repo https://github.com/daviel/teeworlds-snap.
I tried to get the official community to support the snap here: https://github.com/teeworlds/teeworlds/pull/2083