Cropped screenshot from the game featuring the infamous smile.
Touhou Chouseisho ~ Sapphire Panlogism (東方潮聖書 ~ Sapphire Panlogism) is a fan-made Touhou Project game made using the Touhou Danmakufu ph3sx shooting game engine, created by Team Urban Magic. The game features a 6-stage story mode, along with an Extra Stage and an After-Extra "Carrefour" Stage.
It is notable for an in-game portrait of Reimu, as shown below, which briefly spawned a short trend of redraws and memes.