Let's Play Touhou Koukishin - 15 (Postgame) - The Labyrinth swallowed all...
9Maids were stranded, Vampires drowned in the depths, the Gensokyans vanished there.
This is Adventures of Scarlet Curiosity, released on August 16th 2014 for Comiket 86. Its creator Ankakesupa decided to make another 3-dimensional action game, but added more depth this time with equipment, additional customization and 2 new main characters. While still young at the moment, this game has quickly caught on, even with us non-japanese as you will see.
If you want to make the experience of this Let's Play more complete, check out one of these forum-threads below, the one of your choice. They will eventually contain additional information to all the episodes.
Forum-thread Nr. 1: http://socksmakepeoplesexy.net/socksforum/viewtopic.php?f=23&t=1560
or forum thread Nr. 2: http://www.shrinemaiden.org/forum/index.php/topic,17638.0.html