I wonder if a lawyer can comment on the implications for the interaction between games and First Amendment case law. Specifically, I'm pretty sure I remember (vaguely) some suit coming down to a game publisher saying "this is speech, you can't censor us" and the judge deciding "it's just a program, yes we can."[0] It strikes me that if the NEA is treating games as a form of art and in the same category as (say) a film or a radio show, it's harder to make the claim that it shouldn't have the same legal protections. (But IANAL, which is why I'm hoping someone else will comment. :)
[0] Prompting the Penny Arcade quote, "If games can't communicate ideas, then why does he care who buys them?"
I can't remember any successful attempts at censorship in the US, but not for lack of trying. I think all the claims were overturned for the reasons you state.
The only effective way of censoring a game in the US is for Walmart to threaten not to sell it.
I've never heard of either the quote or the underlying case (might not be an American case?), but code is speech. A law directly solely at the code or content of a game would be struck down by the (US) courts. And indeed, nearly every (US state or federal) law so far directed at regulating the content of games has been struck down by the courts.
The execution of a program is "action" and can be regulated if it runs afoul of laws on action, i.e., in the sense that yelling "fire" in a crowded theater can be outlawed. It would be an extremely narrow set of circumstances in which such a law on video games would be allowed. The (US) states have tried to regulate video games many times, and have failed just as many times.
[0] Prompting the Penny Arcade quote, "If games can't communicate ideas, then why does he care who buys them?"