Okay, working on limited knowledge from past misdeeds but here you go (Last trip to the peninsula was Fall 09' so cultural data is current as of that, but their culture also has a habit of changing very slowly):
Korean women are still fairly conservative as far as dress, personal appearance and decorum are concerned. There is more western influence being seen in the younger crowds (teen-college), but to get ahead in life (good paying job, advantages in education for the kids, etc.) you still need to pander to the older generations who are still in positions of authority. So, Korean women would most likely not like to be portrayed like the pictures we've seen of Blade and Soul. On the other hand, the pop singers of Korean fame these days are fairly risque even by our standards, and their influence does grow. Really, target audience is going to be pivotal for any efforts directed towards the Korean peninsula.
Amusingly enough, and I don't have stats, just my observations from my previous misdeeds, computer games are pretty huge over there (5 million-ish play Starcraft at least casually, and it is considered a national sport). E-gaming is actually a way to make a living, and the salaries some of those people rake in are comparable to some of our own pro-athletes. That said, you can check the standings all you like, women are in a stark minority.
There is less of a true spirit of individuality and more of a communal follower-ship dynamic present in society. Current issues that work to our detriment in attempting to get people to see anything in our perspective are as follows.
Target age groups: Too young and they have no influence, too old and they won't have a reason to care or sufficient cause to speak out. This isn't an area that's really easy to exploit because it really doesn't effect them and their economy as a whole, and if nothing else anti-American sentiment is slowly on the rise again in the nation's youth through younger college age work force (granted this is usually subject to which way the wind blows a given day, and the current status of the Korea-US FTA, but that is a different discussion for a different time).
Style of gaming: The preference for them is competitive gaming. City of Heroes did not resonate with them at all, and with our lack of PvP options, one of the primary stress relievers and status builders in their gaming mindsets was completely nixed. Frankly, our game doesn't have much to offer them, and never really did. Also, games come and go for them like any other fad. I doubt its uncommon for them to see a game go dark. Hence, in the U.S. we've still got older games, but most NC titles have been pulled off line at some point or another (Tabula Rasa, Exteel, Dungeon Runners). When they're done, they're done. That's the mindset.
Corporate Communal-ism: One corporation doesn't get in the chili of another corporation in any overt ways. You aren't going to get people who work for a living in company X saying anything about anyone other than their own company, and that is only to tow the company line. Organizations are like family extensions out there, and they believe in very large extended families. Tangent-If you think travel is a nightmare here on Thanksgiving, you should see what traffic looks like there on 추석 (Korean Thanksgiving-Aug 15 on the Lunar calander, roughly pronounced Chuseok (By the way, I really hate attempting to do Korean phonetics into English-they never Romanize quite right)).
Internet society: Trolling, cyberbullying, and otherwise just absolutely flaming people to death for daring to be different (culturally 'different is wrong' is the mindset not the 'different is different' we have here) is rampant. There really is a stigma about doing things in untested ways that really get's their collective hackles up. You can rise against your peers and outdo them in the standard ways: academically, physically, charismatically, but if you are somewhat of an individual, quirky, or downright weird people will collectively make your life suck.
We're not Korean: This is probably the biggest problem any efforts to sway the masses will face. They will protest the hell out of a domestic issue, and some of their protests make ours look fairly tame. However, City of Heroes is a foreign issue dealing with foreigners and frankly they aren't likely to care. Most Koreans do not ever leave the peninsula, and while they are very good trading partners-sometimes-the average person is fairly xenophobic and is prone to openly stare at foreigners in their streets. It can be kind of creepy at times.
That's it of the top of my head, but I'm fairly certain I'm forgetting stuff.
I'm genuinely sorry for a post that is a lot of problems without solutions, but my arena is not the corporate setting. I happen to know a few things about the society and language, and I feel it is best to be forewarned about any potential pitfalls or societal idiosyncrasies that may hinder rather than help.
That said I very much encourage all efforts with any plans to deal with the people directly. Finding expats with current knowledge of people they can talk to or what websites and forums are likely to get any traction is the best information resource I can think of at this time. I've got neither, and aside from being able to poorly and slowly translate the language (my skills are really not what they once were, and my time is really not my own these days), bits of cultural data is about the best I've got to offer these days.
Happy hunting and hit me up with a message if you need anything more in depth or if you want to yell at me for the pessimism.
-Opti