Here you go, all of them are free to play, the introduction taken from web
Gunz Online: http://feature.mmosite.com/gunz/
"Have you ever dreamt of becoming a cool character or hero, like you see in movies, animations, and games?
GunZ is an online game that enables you to realize such a dream! GunZ is not your ordinary gunz fighting game. It allows you to imitate a famous hero, create your own fashion style, and perform a number of different actions such as shooting or stabbing whilst running and jumping on the walls.
Soldier Front: http://feature.mmosite.com/soldierfront/
"The military FPS(First Person Shooting)game"Soldier Front"implements distinctive task force strategy found in today's modern combat.
With comprehensive research from military personnel in the film, "Taeguki", Soldier Front was developed to follow a sildier's perspective in every aspect possible to create the most realistic and unique experience anyone can have."
Wolf Team: http://feature.mmosite.com/wolfteam/
(2nd cb will start at July)
"WolfTeam is a softnyx`s new FPS online game of 2007.
A number of people with similar base arrangement to wolves¡¯ have been discovered in the process of antidoting DNA of mankind of near future."
Phylon Online: http://feature.mmosite.com/phylononline/
"Phylon (from the Greek Phylon, meaning tribe) combines the fast-paced action of an a third person shooter with the persistence and depth of an MMO. "
War Rock: http://feature.mmosite.com/warrock/
" War Rock is a unique on line, modern military shooter that offers exciting, competitive game-play and is a MUST HAVE for consumers seeking a new interactive entertainment alternative within the tactical warfare gaming genre. "