I don't think making games or films on it is gonna change anything. As long as the majority of people see nudism as a quirk rather than something normal these games or films will never make it to become popular enough, and people who would actually watch your film would just treat it as a yet another erotic movie.
Not to mention you need budgets and tons of professionals to make it appealing to the public and not yet another B movie no one ever heard or cares about as first and foremost it should be a good film.
Naaah.... it doesn't need to be something that big... and it won't be necessarily be treated as something erotic.
Again... any kind of content would do, as far as it contains nudity being depicted as something normal at any point.
To give bigger examples, even games as Rust, or Conan Exhiles, wich are survival games, but where the character can be nude, as far as they don't ave any equiped item, and it fits perfectly with the environment of the game, without it feeling forced, or even games as Red Dead Redemption 2 or GTA V, where the animals have visible genitalia (it may sound ridiculous, but in a world where even animals are usually censored in games, drawings and animations, ven this is something) can make a huge difference for slowly getting people more used to nudity as something normal.
Now, going away from the big budget setting, we could for example see a huge amount of indie games developed by independent creators, cool webcomics or even short animations around the internet.
A lot of kinds of content can be produced by one person, or small groups, and a lot of it can be interesting enough to get the attention from a lot of people.
All that would be necessary is for someone to sneak a bit of casual nudity in this kind of content! ^^
Yes... it is true... there would be people that could be attracted to it perceiving it as "erotic", but these ideas would slowly fade as they notice.. that there is nothing there for them. So they would either start getting used to perceiving that nudity as "nothing special", or they would just get bored and go see something else.
And yeah... It is true that smaller projects wouldn't call that much of attention, nor get huge publics. But it doesn't need to... everything starts small... baby steps... all we need is just more content in general.
Also, big budget is not necessary to be mainstream appealing. The "mainstream appeal" is just something that is interesting. Something that people can like and identify with. Something that is charismatic and interesting. Something that a lot of differente people could like, even if it doesn't actually get to reach the "mainstream".
In other words, we need to create content that is actually interesting by itself. Content that we would want to consume, regardless of the nudity...
The nudity must be just something that is there... just there... and not the main reason why we are going for the content in the first place.
And that is how this more casual view on the nudity would start getting more space on the society as a whole.