Impostor
How about looking for a mimic inside apartments with a lot of objects? One of the objects inside is the monster and you need to find and secure him. Item descriptions will lead you.
About
Jam: Ludum Dare 33
Theme: You are the Monster
Date: August 2015
Controls
WS - toggle camera views
LMB - mark suspicious item
Space - highlight mimic (use for hint)
Credits
Ilya Voronov - Game design
Andrey Viktorov - Art/Music
Anton Tarasov - Code