@neo It is a mistake to think of game art, music and storelines in the context of assets, which have the sole purpose of exploitation for profit.

The acceptability depends on implementation specifics - whether the proprietary data is not executable or is executable and contains scripts - the former is not software, the latter is software.


I don't know what the hell "closed source" is meant to mean in relation to game art.

It's not a big deal if you have a png of an image rather than an xcf file, as loading that png into GIMP and making whatever changes you want is trivial - very much unlike trying to modify obfuscated game scripts.


Assuming those games don't use proprietary scripts, it isn't a loss of software freedom to use the proprietary art files, but to be honest, if they have been replaced with free versions, you should be using the free replacements - as you're free to modify and share those as you wish without having to risk infringe copyright law.

In some cases the experience you get running the version with the replacement art is better than the original - for example DOOM vs Freed∞m (you can configure Freed∞m to not have the gun shake that somehow induces motion sickness that faces many people who otherwise do not experience motion sickness).