Twilight Frontier (黄昏フロンティア), also known as Tasogare Frontier or Tasfro for short, is a widely popular doujin circle known for their quality doujin games of varying genres. The games developed by the circle are often derivative works of other widely-known games while few others were actually made in collaboration of other doujin circles, such as ZUN, the creator of the Touhou Project, and 07th Expansion of the Higurashi: When They Cry fame.
Some of circle's most notable titles are the Eternal Fighter Zero series of fighting games, the official Touhou fighting games such as Touhou 07.5 ~ Immaterial And Missing Power, and various fan-made Touhou games based off other popular video game franchises.
Twilight Frontier's website can found here (Japanese).
Doujin games developed by Twilight Frontier:
- Eternal Fighter Zero (2001) — A fighting game featuring characters from various visual novels by Key Visual Arts.
- Eternal Fighter Zero -RENEWAL-
- Eternal Fighter Zero: Blue Sky Edition
- Eternal Fighter Zero: Bad Moon Edition
- Eternal Fighter Zero -Memorial-
- Touhou 07.5 ~ Immaterial and Missing Power (2004) — A fighting gaiden game to Touhou 07 ~ Perfect Cherry Blossom.
- Super Marisa Land (2005) — A Super Mario Bros. clone staring Marisa Kirisame. Also known as Marisa La.
- Mega Mari (2006) — A Mega Man parody staring Marisa and Alice.
- Higurashi Daybreak (2007) — A third-person shooter in collaboration with 07th Expansion. It was later released for Sony's PlayStation Portable.
- Higurashi Daybreak Kai (2007) — An expansion pack for Higurashi Daybreak.
- PatchCon! Defend the Library! (2007) — A real-time strategy game where Patchouli uses a team of five Touhou character dolls must protect her library from other rival dolls trying to ransack it.
- Touhou 10.5 ~ Scarlet Weather Rhapsody (2008) — A follow-up gaiden game to Touhou 10 ~ Mountain of Faith.
- Touhou 12.3 ~ Hisoutensoku (2009) — A stand-alone expansion pack for Touhou 10.5 ~ Scarlet Weather Rhapsody.
- New Super Marisa Land (2010) — A sequel to Super Marisa Land.
- DynaMarisa 3D (2011) — A Touhou-meets-Earth Defense Force 2017 fan-game staring Marisa Kirisame.
- Grief Syndrome (2011) — A beat 'em up game based on Puella Magi Madoka Magica.
- Satori Komeji's Mental Education (2012) — A Touhou puzzle game staring Satori Komeji.
- Touhou 13.5 ~ Hopeless Masquerade (2013) — A gaiden fighting game to Touhou 13 ~ Ten Desires.
- Touhou 14.5 ~ Urban Legend in Limbo (2015) — Another fighting game spinoff to the Touhou series.
- Touhou 15.5 ~ Antimony of Common Flowers (Demo 2017) — Yet another fighting game spinoff to Touhou.