That's Not My Neighbor is a horror game where you play as a security guard who verifies the identity of people entering the house and not illegal intruders.
Your apartment building can be threatened if there is an intruder, so you are tasked with verifying the identity of those who want to enter the apartment. If someone is safe, you can let them in, but if someone is suspicious, you cannot let them in. Just a little carelessness, your apartment will be in danger if you let the wrong person in.
Verify everything noted on your ID card or resident list. Carefully review personal information and resident photos so that intruders cannot enter your apartment.