(Pfp not mine, here's the page: "https://www.deviantart.com/bradrigney/art/Containment-Breach-Sub-Level-5-90738442". Inspired by Pressure on ROBLOX but not exactly it.)

Hadal Blacksite. After lock down, you choose who you want to play as, there's multiple monsters and creatures which breached containment.

You can find survivors, or encounter monsters, or both. If you need a place to start, read the Description.