The list of games where basically everything is "open", including asset-related game data is very small and usually games i never heard about... because simply not a "top tier". Many of them are inside the first list:

https://en.wikipedia.org/wiki/List_of_commercial_video_games_with_later_released_source_code

However... any quality game in general with a open source engine, still got its assets "closed", just as i said.

In theory dependable on games there can be different rights granted but in general "open source games" are already a rarity in the single digit number (from my collection about 1% to be more precise) and those who made their assets openly available are "close to none".

I think, asking for, not much can come out of it: I still find it important for everyone in order to realize "how hard" most games are actually initially protected and that "DRM free" is just "the middle ground", like 5 fingers... yet still far away from 2 hands or 10 fingers.

This list is probably nearly complete but i would say there are maybe 10 "well made" projects out of 370+ not much more, the other stuff i would not bother with but no one knows "your standards":

https://trilarion.github.io/opensourcegames/games/libre.html

Speak in plain english and research the terminology involved here. You're not impressing people engaging in discourse articulated with ornate and sophisticated parlance.

Hm. It seems to me that you've overused or become over-reliant on your thesaurus or similar tools to increase either your lexicon or just the variability of your expression, because your manner of typing in this topic is unnatural when compared to your organic way of writing, when you aren't anticipating a specific audience. Or at least, that's what I surmise. Am I wrong? Either way, I hope you are able to improve your writing ability as you so desire.

I remember when people tried to do that with ZZT and Game Maker.

I read the whole thread, then reread the first message. I'm thinking maybe "speculated" might be "speculated about negotiating". So instead of buying ownership of the engine, pay the owner to open source it. Then work with it.

Aye? And what of the 6+ figure price or the many middleware bits with shall we say, less than open terms?

A game desinger or publisher deciding to make his or her source code public is not the same as open source.
Problem with open sourcie games is the good ones are few and far between; most people who are good at designing games liked to be paid for their efforts.