Historical: This game was done in 2006 and by a programmer (learning to tinker with Blender at that time) not an artist. So forgive 3D graphics that look quite dated now :)
You want to see something pretty done with Castle Game Engine? Check out examples/fps_game ( https://github.com/castle-engine/cast... )! The fps_game demo was done by real artists, and in 2022, and it looks amazing.
This is demo movie from my 2006 game "The Castle", short gameplay sequences and shadow volumes fun. The game is free software, available from http://castle-engine.sourceforge.net/... .