patchcon

PatchCon! Defend the Library is a real-time strategy game developed by Twilight Frontier (tasofro) and released on December 31st, 2007. You control various characters (dolls) from the Touhou series in great quantity and repel waves of attacks from your enemies. The main goal of the game is to protect the books in a bookcase from these various waves, but it sports a variety of different extra modes as well.

Official page and video: http://www.tasofro.net/patchcon/index.html

This tag implicates touhou (learn more).