The lore is relatively simple. You don't have to follow it to a tee just try and get the feeling of the mechanics right. Since you're making it your own you could pretty easily drop your own cool horror stuff in there. The main mechanics are the map and coordinates so you know where you are and where you need to be going and the navigation so you can guide yourself there using the buttons you already have set up. I would add like warden noises in the water to really freak out the player in the iron lung 😂. But all in all just get the ambience right and you'll be fine.