For my mcyt kins the minecraft universe generally works the same for them all even if they're not from remotely similar canons. But basically reality is made of code. There's an "earth server" which is just earth but with Minecraft physics, and the single/multiplayer modes were a separate thing people could access and go into.
Basically you play Minecraft in Minecraft which includes everything in your average Minecraft experience. Except you actually live in it. It's not like a VR world or anything— it's an actual thing that exists that you can live and breathe in.
Death is only permanent if you die in the earth server, most of the time.
Oh mods exists too so that's funky. Only for the single/multiplayer worlds though. If you try to put a mod into the "earth server" you'll probably get thrown into jail immediately since you're literally altering reality.
My Roblox kins are a similar case to the mcyt ones except that there "Robloxia" is earth. Don't think any background music or the health bars were diagetic... Avatars and usernames were, though.
Then for Pressure—
As Expendable I know about Search Party (the ost) but don't actively hear it myself?
I know it's happening, know how it sounds like and I know where in the track we currently are, but I can't actually hear it.
Entity can though and enjoys the ost, so since Entity is controlling my body, I'm pretty sure that's how I have that knowledge.
