Available from https://flathub.org/apps/details/jp.yvt.OpenSpades #OpenSpades is a free and #OpenSource online first-person shooter created by Ben Aksoy, featuring fully destructible terrain and plenty of game modes (including capture the flag) created by the community.
For those who don't know, Ace of Spades was this awesome free game that some guy made with voxel graphics, battlefield style gameplay, and building/digging mechanics. You could build fortresses, tunnel through to the enemy base; it was just an all-around good time.
Then some company bought the IP from the creator and turned it into some shitty pseudo-fortnite game. Some people who appreciated the original game kept some servers running under the title Build 'n' Shoot. The service is still running, and you can download a free program that connects to them to play in matches.
Super glad to see that it's being kept alive, it's such a fun and simplistic game, and anyone can play it with a halfway decent PC.
Oh hell yeah, I used to play the shit out of Ace of Spades but I stopped after the buyout. Think it was Jagex that bought em.