Gensou Shoujo Taisen ("Fantasy Maiden Wars") is a Touhoudoujin game series in the spirit of the popular Super Robot Wars games, created by Sanbondo. The game is divided into four parts (three of which have been released so far), and loosely retells the story of every Touhou game from the 6th through the 12th, while attempting to create a more unified story between all of them.The first part, Kou (Scarlet), retells the story of Embodiment of Scarlet Devil and has been translated into English by Deranged. The patch can be found here. The second part, You (Mystic), combines Mountain of Faith and Perfect Cherry Blossom, and the third part, Ei (Eternal), combines Imperishable Night with Subterranean Animism.
This series contains examples of:
Big Damn Heroes: Prevalent all throughout the games. In particular, the Scarlet Devil Mansion's inhabitants tend to show up as reinforcements during climactic battles. In Kou, Sakuya appears to assist you on Remila's orders when fighting Flan. In You, Patchouli and Koakuma show up to lend their aid against Sanae and in Ei, Remilia flies in to save Sakuya when fighting Eirin.)
The Cavalry: Mima appears to save Marisa in the Underground.
The Chessmaster: Kanako and Suwako appear only in cutscenes in Kou, seemingly planning their move for You.
Combining Mecha: After being defeated individually, the Prismriver Sisters huddle together to become a single unit, which is treated mechanically like an SRW Combining Mecha. This results in the Three Fairies of Light deciding to "combine" as well... in a scene which parodies Tengen Toppa Gurren Lagann.
Continuity Porn: The game blends the story of the official Touhou games, including the PC-98 continuity, into one.
Cooldown Hug: Happens twice in Ei, first with Remilia hugging a berserk Flandre in a special attack-animation cutscene, and later with Rin and Utsuho, although the latter only partially succeeded because Utsuho's power was no longer under her control even after she regained awareness.
Cultural Translation: The subtitles "Kou", "You", and "Ei" come from "Koumakyou", "Youyoumu", and "Eiyashou", the Japanese parts of the first three Windows Touhou games' names (which are relatively obscure in the English fanbase). The Fan Translation renders them as "E" and "P", from their English portions, "Embodiment of Scarlet Devil" and "Perfect Cherry Blossom", which more closely fits the naming scheme of the Super Robot Wars games.
Final Boss: Flandre in Kou. Yukari in You. Utsuho in Ei.
Final Boss Preview: You meet Flandre as an NPC as Marisa. You can beat her, if you can take her down with Marisa only. You also meet a pre-powered up version of Utsuho as one of the weakest bosses in the game, to foreshadow her character development.
Good Bad Bugs: One of Yuyuko's Personal Skills, 'Return to Yomi,' is stated to give her half the remaining SP of any defeated ally character. What is does is give her half the remaining SP of any defeated unit on the map. Combined with her 'Butterfly Dance' spirit command (+5 Power to all allies on her map), Yuyuko can have your entire party at max Power by turn 2, and still be packing a full SP bar.
Leitmotif: Everyone has at least one. Sakuya, Nitori, Youmu, Aya and Sanae have different ones both as an enemy and as an ally. The three fairies gain one for their Combination Attack and another one in Combining Mecha form.
Hopeless Boss Fight: The fight with Yorihime in Ei, if you choose the dialog options that let her use her full power on you. She has enough evasion to dodge anything but an Always Accurate Attack, and can attack more than once per turn with attacks that exceed the game's accuracy limit. However, you can time out all her cards and beat the mission by running away.
When Lily White joins your team she has only a single attack, low stats, and is practically an Emotionless Girl; she powers up (and brightens up) significantly once you get closer to where all the Spring was taken.
Both Reimu and Marisa change sprites and movesets (and theme music) partway through Ei, just in time to use them against each other in the obligatory Let's You and Him Fight from Imperishable Night stage 4.
In contrast Easy and Normal compare themselves to more modern games, Alpha and Alpha Gaiden.
Readings Are Off the Scale: Any enemy unit whose current HP is exceeds 10,000 will have both their current and max HP values replaced with question marks. Their health bar still shows the percentage of their health, though.
Some of the older Super Robot Wars game did that too so it might have been done on purpose.
This happens in the plot as well when Keine measures Yorihime's spiritual energy after letting her use all her power.
Recycled IN SPACE!: Lampshaded in Ei, chapter 48, which is titled "Gensou IN SPACE". Naturally this chapter is when the party visits the moon.
Shout-Out: Tons, to Super Robot Wars itself as well as the countless mecha shows featured in the series, ranging from character dialogue, attack animations, to even musical nods.