Sponsored by Korean Govt!!!
it's a collection of games developed by smaller companies.
I dont' know much about other games. But, "Navy Field" is supposed to be a really good game. A bit of warning is that it has a pretty steep learning curve.
There are other interesting looking games like MMO golf game and a game that looks pretty much like Mabinogi.
Anyways, enjoy~!
Free Beta Games
"Edit"
My boss just pointed out that the link to Navy Field is broken from the gamengame.com site. So, here is a direct link to the Navy Field site.
Navy Field
I am not sure about other games' links are working or not. The Shot Online seems like it's working. They usually have a link to the actual site on the pages for the game. So, you can go directly to those sites to see if the downloads are working or not.