The game was announced in January 2008, and has been subject to delay and changes to release platforms; a closed beta-test began in December 2011 in South Korea.

[1] The Chinese version of Kingdom Under Fire 2 entered a no-wipe Closed Beta state in March 2017.

When controlling other units, the game played like a typical RTS; cannons for example could be used to break down castle walls and spearmen could be used to protect troops from cavalry.

[3] The plot of Kingdom Under Fire II came chronologically after the events in Circle of Doom – which took place within the alternative dimension of the game's antagonist – Encablossa.

In an interview representatives from Blueside and Phantagram stated that 90 persons were working on the project, and that the game had been delayed due a shortage of manpower caused by simultaneous development of console and PC versions, as well as delays due to inexperience with online game development.

[10] In November 2010, Blueside announced the development of a PlayStation 3 version, initially with a projected release date in 2012, citing the suitability of the PS3's online mechanism's for adding updates.

[17][18] In a November 2019 interview, Kingdom Under Fire II creative director Joo-Bo Kim confirmed that there were no current plans for a PlayStation 4 version and that development was focused sole on PC.

The developer revealed that there will be no data wipes after the launch of open beta, so any progress made during the testing phase will carry over to full release.

[25] On September 17, 2021 Gameforge announced that it was discontinuing operations of the North American and European servers and that they would be going offline on October 26, 2021.