so far i believe just to be only 2 at the moment, one of them is Oh! Baby! "something" i'll double check again whenever i get a chance.
South Korean games are very interesting, they try to be their own thing but end up desperately trying emulate Japanese games, Like Pump it up for example. A little googling revealed Magna Carta: Tears of Blood to be a game made for PS2, it was not a port of the PC game either.
Mystic Nights (http://www.koreanversion.com/sony/ps2/mystic-nights) Gran Turismo Concept: 2002 Tokyo - Seoul (http://www.koreanversion.com/sony/ps2/gran-turismo-concept-2002-tokyo-seoul) Come on Baby (http://www.koreanversion.com/sony/ps2/come-on-baby) though this was later released in Japan under the Simple 2000 series thereby making it technically no longer a Korean exclusive
Although released only in South Korea, GT Concept 2002 Tokyo-Seoul still is a japanese developed game.
I'm curious because I've come across a my stash of korean ps2 test machines. There can't be many of them made. I'm wondering why they even made them.
Every game released (even ports) for the Korean region (licensed with a Korean code) would probably have to be submitted to SONY (in the form of a master disc) for review first. The DebugStation (DEX) is not for debugging, but for just testing the game on retail-like hardware prior to submission. As of their March 2003 tool, there were only a few regions of DEX consoles listed in the SONY adjustment tool: DTL-H50000 (Japan) DTL-H50001 (US) DTL-H50002 (Australia, but I think that European developers use these units too) DTL-H50005 (Korea) DTL-H50006 (Asia) DTL-H50008 (Russia) DTL-H50009 (the one and only model for China, which has a region for itself) Japan, US, Europe and Korea definitely have Technical Requirement Checklists (TRCs) for themselves. I've never heard of a game properly released in the Asian region though; it is NTSC-J, so we usually see Japanese games around here for it (unless we mod the PS2s to play English games).
To be fair I learned about Pump it up in an old Tokyo pop magazine before I knew of DDR. But DDR did indeed come first. Personally I prefer Pump it up. The srrow placement is more natural and I can play it without cramping up right away.
Don't forget about the obligatory 'karaoke' games: LuluRara Vol.1, Vol.2 Eye Toy Groove has content exclusive to the Korean version Here are a few more Korean-developed PS2 titles I didn't see mentioned yet (not Korean exclusives): Pump it Up Exceed Tomak: Save the Earth: Love Story Axel Impact War of the Genesis