Modanung You're stuck in a loop of referring to software-specific definitions. I repeat: It is rare for games to consist of only software, making your point moot.
You are stuck in a loop of trying to iron your - quite selective - definiton over a general one. I repeat: Most people refer to free/libre regarding the code base, as the free software movement (where both terms originate from) is originally not about assets.
Since you started of about games: Historically, it is rare for games to be video games at all. Chess, as a game, is public domain - however, you still have either to buy or make the figures yourself. Still, one can not argue that this makes the game not public domain - as we use the term "game" for the underlying logic, and not the actual iteration :p.
On the other hand, most of the video games on the list you linked still rely on non-free hardware and software (the infamous BLOBS) - as far as I know, playing Xonotic or SuperTuxKart on a full-FLOSS system like Dragora is difficult, if not impossible. Saying that a game is intertwined with its assets, but ignoring the hardware that is needed to play it is rather inconsistent, or not?
Since the libre game wiki shares your definition, naturally all examples listed there fit your definition. Its your bubble. Games like Warsow, OpenRA, or Zero-K are, however, also free, libre video games that you chose to exclude.
As described above, I don't think that the definition that is prevalent there is helpful for the greater cause.
