Cube Engine 1 and 2 touted as the smallest (in terms of file size) FPS Multiplayer game. It's also free. Unknown if the community is still booming as I have not played it in a long time. Eh while we're at it there's also Warsow but this one I know the community isn't as great as before. Source: about 1 year ago

I'd you want something a little more advanced but straight forward I highly suggest Warsow. It's a free first person arena shooter that plays very much like Quake. Source: about 2 years ago

Warsow is also quite good and very close to late 90's shooter's idea of multiplayer https://warsow.net/. - Source: Hacker News / about 3 years ago

Playing games is part of who we are as humans. Ditto for making games. From Nine Men Morris to Shattered Pixel Dungeon, Mindustry, and Warsow, people have been making and playing games for free. We don't need a games industry in order to have games. Source: about 3 years ago

Https://vginsights.com/, or check out the other articles in the blog that OP linked to. Source: over 1 year ago

1) Use these websites to find and evaluate publishers. Https://vginsights.com/ Https://gaminganalytics.info/index Https://games-popularity.com/. Source: over 1 year ago

Darktide over 2 months has generated $55.8m gross, or 75% of what V2 did in 3% of the time (https://vginsights.com/). Source: over 1 year ago

Since Steam made it more difficult to get numbers, this website is one of the better ones I have found. Https://vginsights.com/. Source: over 1 year ago

I got it from where someone else posted it in the comments: VG Insights. Source: over 1 year ago