A 2D fighting game based on Tsukihime. Originally a collaboration between TYPE-MOON and French Bread (known as Watanabe Seisakujo before 2003), the game was originally released at the 2002 winter Comiket (C63) as a doujin fighter. An expansion patch called Re-ACT was released two years later in May 2004, and a patch called Final Tuned was later released for free in July 2005.
While the game was developed by French Bread, TYPE-MOON was closely involved with its production, with character design and CG by Takeuchi, music by KATE, and most importantly, script by Nasu. Even though in name this is a Tsukihime doujin, in reality it had more or less become an official TYPE-MOON game. It also played a big role in promoting the popularity of Tsukihime.
Thanks to its balanced gameplay, high production quality (60 FPS for a doujin game at the time), and fluid control, Melty Blood became a popular fighting game among fans and received many praise, and tournaments were held in various places in Japan. The Re-ACT patch further increased the game’s success. In 2006, the popular international fighting game tournament Tougeki began featuring Melty Blood as one of its events.
Originally, only six characters were playable, with eight more being unlockable through Story Mode. A later update (the "Nero" patch) all the characters playable from the start. Some speculate that the reason for this patch was due to a legal misunderstanding, where TYPE-MOON mistakenly thought they would no longer be allowed to produce updates/patches, and thus made a "last patch" that unlocked the characters as a gift to the fans.
On March 2005, an arcade version of the game titled Melty Blood Act Cadenza was released by Ecole Software, which was ported to PlayStation 2 in 2006. An update of Act Cadenza, entitled Act Cadenza Ver.B, was released in the arcades in December 2006 and later ported to the PC in 2007. The latest installment, Melty Blood Actress Again, was released by Ecole in September 2008 in Japan. Melty Blood has also been adapted into a manga series drawn by Kirishima Takeru and serialized in Kadokawa Shoten's Comp Ace.