The problem with these games is not that they are commercial. (We see nothing
wrong with that.) It is not that the developers sell copies; that's not wrong
either. The problem is that the games contain software that is not free (free
in the sense of freedom, of course).
Nonfree game programs (like other nonfree programs) are unethical because
they deny freedom to their users. (Game art is a different issue, because it
isn't software.) If you want freedom, one requisite for it is not having or
running nonfree programs on your computer. That much is clear.
(...)
Free software is a matter of freedom, not price. A free game need not be
gratis. It is feasible to develop free games commercially, while respecting
your freedom to change the software you use. Since the art in the game is not
software, it is not ethically imperative to make the art free — though free
art is an additional contribution. There is in fact free game software
developed by companies, as well as free games developed noncommercially by
volunteers. Crowdfunding development will only get easier.
But if we suppose that it is not feasible in the current situation to develop
a certain kind of free game — what would follow then? There's no good in
writing it as a nonfree game. To have freedom in your computing, requires
rejecting nonfree software, pure and simple. You as a freedom-lover won't use
the nonfree game if it exists, so you won't lose anything if it does not
exist.
https://www.gnu.org/philosophy/nonfree-games.html
