not sure if it was posted before but there is a korean game called chaos gem at

http://www.cagemon.com/

also this is kind of old but not sure if its been posted theres a cool korean running/racing game called TalesRunner at

http://www.talesrunner.com

you can also find alot of korean mmos at http://www.gdaily.co.kr/content/list.asp?p_idx=1