Alicia Online was originally a Korean MMO, developed by Ntreev Soft and published by Gametree (now known as Smilegate).
The original Alicia Online servers closed down in February 2014. The 2.0 version of Alicia Online, which was a completely modified version of the game, shut down in October of 2012 after a week of its open beta. Subsequently, Alicia Online closed down due to financial reasons after the loss of player's interest in the game due to 2.0's failure.
A private server was developed and has kept the original gameplay mechanics of the old Alicia Online 1.0 version while also implementing features from the 2.0 version.
Here are the Alicia Online (2.0) files: Alicia Online (2.0)
Here is the unpacker you use for res.pak and res.pak.001 (res.pak.001 will be a .zip, so please unzip it first): Universal Unpacker 1.3.2
Alternative Alicia Online (2.0) link: Alicia20_setup_001 (original uploader)
Alternative Universal Unpacker 1.3.2: http://hsreina.shadosoft-tm.com/ (original uploader)
If you need any help or have questions, please don't hesitate to ask!