...how affected would you be by it?
I don't see this ever really happening. There will always be mature games, even if some kind of underground indie market emerges, but I've been thinking about this lately and in some ways I think it wouldn't immediately ruin games.
I'm not against violence in games. I laugh at over-the-top stuff like the bloody mess perk in Fallout 3. I like the idea of slicing enemies up in MGR:Revengeance. I like fighting games, Condemned 2 and any good 3rd person melee system. I love starting chain reactions of car explosions in GTAIV. I will never be someone with any credibility to argue against game violence because, once in Vice City, I snuck into the strip club with a sniper rifle and blew the heads off all the dancers. I like crazy exaggerated violence just fine. I like it in movies like Evil Dead 2, Dead Alive and Riki-Oh.
This kind of thing can be highly entertaining, like the Three Stooges, but what I get tired of in games is the mundane, constant violence we get out of most shooters. If there's one thing I hate in any game it's when your only interaction with the world is shooting things. The only games I really like that come close to that description is Half-Life 1 & 2 because they were innovators in making shooters with a deeper sense of interacting with the world. There have been shooters since that I can get into. I'm pretty into the last 2 Far-Cry games, but overall, I'm not a huge fan of the genre. As important as I will admit Doom is, I am still more of a fan of Ultima Underworld.
Most of the games I really like have plenty of violence in them, but allow you to decide how much you want to engage in. I prefer stealth franchises like MGS and Thief or at least games that give you a choice of stealth like Deus Ex. That's not to say that stealth always equals non-violence. I'm a big fan of Tenchu and that's all about sneaking up on and straight-up murdering people without detection. I also really love games like Fallout and Arcanum that allow me to talk my way out of a lot of situations.
Now, banning violence would probably ruin a lot of those games because it would remove the choice, but I also think restricting game developers from immediately making the main transaction with the gameworld violent could lead to some interesting new mechanics. Look at Germany where board games and sims have taken off because of lack of access to violent games. While I don't wish to see the entire industry turn into sims. I think we need to start diversifying the kinds of games we're playing a little more. There are still a few decent sim games on the market and we get an occasional great adventure game, but I remember when computer games really started to take over from arcade games and we suddenly had tons of platformers, adventure games, sims, strategy games and rpgs. While all of those genres are still around, today it's pretty rare to get a game where combat of some kind isn't the most prominent mechanic in the game.
I'm not going to pretend that any kind of violence ban would ever be done right anyway. Back when this actually happened to the comic industry and the strict comics code was enforced it was a huge mess. I love pre-code horror, sci-fi and crime comics and I think it sucks that they were killed off the way they were, but there's this really interesting period just after the code and before the market became dominated by cowboys and then superheroes when publishers like EC (who were doing Tales from the Crypt before) started publishing comics about reporters and doctors. They even had one about psychoanalysis.
In the end, what I'd like to see the most is games that push into these other areas on their own without the government involvement. I'm not discounting that there are lots of indie games that don't care at all about what is popular, but in the case of the big studios, as long as repetitive shooters sell really well, They are just going to keep making them. I loved the first 2 Mass Effects, but would people have played them without the shooting sections? Maybe the Walking Dead proves that some people might, even though that game has its far share of violence and gore and probably wouldn't make it past censors either. It makes me wonder how a huge AAA game based on something like the experimental indie game Facade would do. I guess we can always look to the indies and the biggest, most interesting Kickstarter projects for this kind of diversity, but it would be nice if the top tier of the market was more supportive of more unique types of games.