Deep Secret

From the letters page: Deep Secret: a puzzle game about fantasy, monster girl and parody, developed by Lovely Games. It runs on Unity and puts you in the role of a male protagonist. Status: finished, version Final + DLC. Available for Windows; 187 MB.

From the box: “This is a casual puzzle match-3 game. Players need to use the mouse to select two unobstructed squares, and if they are the same, they will be eliminated.”