First investments into the enterprise that would eventually form the arcade game manufacturer Eolith were made at Kum Gang in March 19941, and although Eolith was founded as an independent company in 1996, Kum Gang published their early arcade games. In the new millenium, Eolith formed a small chain of franchise arcades called G-Park and registered at KOSDAQ on June 7th, as the first Korean arcade game maker2. Besides video games, their mechanical redemption machines Eldorado (Ministry of Culture and Tourism Game of the Month June 2001) and Mugunghwa Kkot-i Pieosseumnida ("The roses of Sharon have blossomed"; Game of the Month November 2001 & Arcade Game of the Year 2001)3. Although some of their Hidden Catch games were marketed in Europe, the global gaming community only really took notice of the company when some of the rights to SNK properties landed in its hands, and it found itself in charge for The King of Fighters 2001 and 2002 (the majority of the game credits still went to the same team as other episodes, though, with only a nominal director and a producer from Eolith staff).
M-Dream was founded by a former Eolith employee and specialized in developing mobile games, mostly ports of famous Japanese arcade games, they had an especially strong bond with Taito. They also developed a couple of online titles, and localized and published a number of PS2 and PC games. In November 2002 the subsidiary M-Dream China was formed4.
After reaching its height in 2001, Eolith came into financial troubles, and in November 2003 merged with M-Dream5. The joined companies operated as Eolith, but M-Dream's Choe Jeongho became its new CEO (from March 2004), and the M-Dream name never disappeared, but even outlived Eolith. Half a year after merging with M-Dream and shifting the main focus to mobile games, Eolith reportedly was in the black again for the first time in three years6.
The merger couldn't save Eolith in the long run, though. In On June 3rd, 2005 it was bought out by another company called Netbrain7, eventually integrated in the pharma company Neurotech and thoroughly restructured. Eolith finally disappeared when it was renamed to Neurotech Pharma on November 8th, 20068. M-Dream, seemingly a separate company again, continued to publish mobile games until 2007, but then quietly disappeared as well (the M-Dream China homepage is still available, but hasn't been updated since).
In May 2008, a new company named Neolith appeared, which seems to own at least some former Eolith properties, as it uses the same logo and continues the Hidden Catch series (which in the meantime had gotten another sequel published by F2System). Not much is known about Neolith, though, as it doesn't have a web presence. It received government support of 160,000,000 Won, but never showed much of a result9.