KOS Secret Operations logo.

KOS Secret Operations, with the acronym standing for "Kill On Sight", is a free-to-play FPS developed by South Korean developer YNK Interactive for Microsoft Windows. It was published in the Philippines by Level Up! in 2009.

The game is Level Up!'s first FPS published in the Philippines. Its closed beta test began on December 23, 2009. Its open beta began on February 12, 2010.^[1]

1. KOS: OBT Servers are finally up!. February 12, 2010 at 4:47 PM. Level up! team. Level Up! news. Retrieved on 2023-12-05.