The White Chamber is one of many exemplary cases of how free games/freeware had been before digital storefronts became widely accepted. 2-10 British and German dudes (+ the one or two women they knew to do a the VO work) working a year or a few for a proud tribute between Event Horizon and Silent Hill, with the sheen and style of Anime. In the limited budget cost of "no profit", a Point-and-Click becomes and easy path forward to develop with. Many of the people involved went on other and maybe greater things down the road (not alone, but with Kairo being a notable example).

Because of how short this game is (1 to 5 hours, depending on how knowledgeable you are of it), a walkthrough will spoil the setups and paths quickly. In whole, a short, well put together creepy experience.

A visually pleasing and respectable game with puzzles as cryptic as figuring out Yume Nikki but without a wiki or walkthrough, leading to one of the earliest brick walls I have seen in a videogame. The abstract presentation of the main hub screen of the exploded spaceship is a visual oddity in the best way. The soundtrack was equally mysterious and beautiful for the time. Though I can't tell if these are just 5 tracks on loop or if there's more because I can't get my head around the heavily abstract puzzles.

The community surrounding Xonotic is a cockroach that's almost as resilient as the Id Tech predecessors proper.
So the original IP holders sell it off to a German studio for a console-only CryEngine reboot, published by THQ? No sweat, here comes Xonotic, a kneejerk fork of Nexuiz Classic, likely created in the same year of the selloff. A new website and Quakenet IRC channel are created.
Nexuiz 2012 releases and bombs. Also THQ goes bankrupt. Xonotic still lives.
Shootmania comes and goes, Ubisoft is underwhelmed by the lack of engagement and shuts it down. Xonotic still lives.
Toxikk is gonna bring back the REAL and HARDCORE ARENA SHOOTER Action (NO REGENERATING HEALTH HERE!! 1999 IS BACK BABY!!!!!!) aaand the game underperforms and the developers quietly shutters it. Xonotic still lives.
Oh my goodness, Epic Games is bringing back Unreal Tournament 4! UT4 is here and real! It's coming to a paid open alpha and uh... whoops haha uhh Epic's got their obscure indie hit Fortnite to maintain so they'll just pretend UT4 doesn't exist. Xonotic still lives.
Okay okay, we know Epic will never touch that property until the Fortnite train dies. But look, Cliff Bazinga's got an arena shooter coming out! It's like the best of Overwatch and Quake combined, look at the hot new eSports tournament they're producing!!
Lawbreakers bombs, Xonotic still lives. (shoutout to Radical Heights LOL)

It's been over a decade and a scrappy arena shooter based off an incredibly hacked apart Quake 1 source port is still able to have pulses of life. I have seen an honest to god Xonotic tournaments livestreamed in this decade, with live commentary. One even topped 69 viewers, outdoing Cruelty Squad in that game's well-earned buzz cycle for that year. And there's a reason for that.

Even the act of getting pubstomped by semi-competitive players is a joy, just from the movement alone. The autohopping can quickly send you flying across the rooms of a map, air control letting the player cruise through like a plane. The weapons may not have a clean eSports™ balance but only a weird analytics nerd would dislike the selection. This is not an 'edgy' pastiche, but a game whose predecessor was released in 2005, one year before Quake 4. Pure iteration.

And it's free, both in payment and in source code. With the exception of Warsow, Cube 2 Sauerbraten, and arguably Quake and Doom, no other "revival" of this genre has dared to take this step for fear of market competition.