This is a compilation of textures from my 2021 game prototype, which I called Cirkuz 33, running on a modified Quake 3 engine. Since the game was a retro FPS, I thought it'd be appropriate to turn these textures into a Half-Life WAD.
About half of them are photosourced, and the other half is derived from AmbientCg, formerly known as CC0Textures. Some textures have their higher-res and/or lower-res variants. I couldn't include the original PNGs due to filesize limits on TWHL. I plan to do some extra digging and put the original GIMP projects as well, and the original photos some of these came from, in a future update.
I licence this to you under CC BY, which really just means: credit me if you use these anywhere. Also, fun fact, this is the 6666th item in the TWHL Vault. :>