Completely subjective list of places with good quality assets (graphics, sounds) in formats useful with Castle Game Engine. See and post on the #assets
channel of our Discord for more.
Game art (3D, 2D, sounds) uploaded by various artsts on clear open-source licenses.
Hint: Do you want to share an asset you made and tested specifically for CGE game? Upload it to OpenGameArt.org with [CGE]
in the name.
3D models, in glTF format, uploaded by various arists. Some free (on clear licenses, like Creative Commons), some paid.
Note: you can also import from Sketchfab directly in CGE editor!
3D models in Blender (which you can export to glTF easily). Uploaded by various artists. All on Creative Commons licenses.