I think it would be great if maybe different NPCs had different patterns/quirks. Like, maybe some are faster, or have a wider range of vision. Maybe some have different reactions, like calling the police, alerting others in the room, or trying to take you down themselves. Maybe you can add multiple levels after the one that currently there that progress the story more and have similar mechanics. Maybe include more mechanics as the player progresses. I would love to see the story expanded more! Of course, only if you want to. That's just my two cents.