Neighbor's doppelganger

In the game, your task will be to allow or deny entry into the building to subjects who ask to enter it. It seems simple, but be careful, you can't miss a single detail, because you can become food for doppelgangers.
You have recently taken a position as a security guard tasked with guarding a prestigious building. Your mission? To verify the identity of every person who wants to enter the building before allowing them in. But be careful: not everyone is who they say they are!