See a demo of the game (that uses my illustrations!) here.
Like traditional Toho games, this fangame has a strange English title and a three-stage playable demo. Here are the character illustrations for the first three stages.
In the story, the balance of power in Gensokyo has suddenly turned upside down. Servants have become masters, and the apocryphal Rin Satsuki has become the resolver of incidents. Who is behind all this? The answer will surprise you.