A work of art should be changeable after a short period of time (say 10
years). The current trend to indefinitely extend copyright is bad. How many
masterpieces were in fact derived from other works of Art? Shakespeare has
borrowed most of his theme (and some content) from other authors; La Fontaine
has mainly re-actualized the Greek poet Esope, rap samples funk, electronic
mainly creates from existing sounds/songs, many movies created on the Web
reuses existing material, etc. And no, the original piece of work will not
disappear behind its derivatives (unless it was mediocre and the derivative
have greatly improved upon it).
Only material directly involving the author's ideas (say a manifesto, a
political speech, a scientific article, etc.) should never be modifiable. I
admit the line between entertainment and ideas may be hard to draw.
And, in all cases, these works should always be freely sharable (at no cost
at least). In a society, it does not make any sense to prohibit sharing!
When it comes to video games, it looks clear to me that the design, the
music, the story (if any) are entertainment material and need not be free (as
in free software). I have not made my mind clear about the rest of the game
(e.g., the physics, the 3D engine, etc.).
