The name of the game is Enter Occlusion, and it isn't a lot like anything else.
There's a whole lot of sandbox science fiction and survival horror that doesn't take place in space or the future, AND there's no undead.
I'll try my best to explain as I am new to this; a back story if you will- Something, to be decided when I know for sure, (whether it be bacteria, a shift in some alignment with Earth, or even whatever you might think is a good idea) has become able to expand water into its gaseous form of cold steam.
Only it's lighter than the air we breathe, and bubbles our atmosphere out, pushing our oxygen into the cratered empty beds we once knew to be the seafloor. Ships are thrown across the sky, only to sink out into the damned dark- crushing volcanic vents that envelope them into giant steel caves. Above this, at the exact mark of sea level, the steam portrays an almost "calm before the storm". The survivors of this fate are struck with an eerie feeling worse than the confusion of the recent events, paired with fear for their loved ones on the shores...
Where had all the creatures gone? Sure, a starfish here and there, and the aquatic plant life that was abundant also seemed very content for it's new surroundings, bustling really. No, they had adapted to something that was far in the works long before they ever cultivated on land. They were floating around out there, with everyone else. This disturbed many of the men, and raised reason for action in the strongest of them.
Though, nothing could prepare them for what was really going on above them. As most neared the coasts, that's when the floaters started falling out. Bloated dead came like snow, sometimes in pieces- but you could see where they would come out a good 6 meters into the fog. They were dangerous, and many parties that had decided to trek to land had to try and wait it out in shacks made of scattered boats and destroyed homes, but it never stopped.
Above, on the "surface", all was not well. The steam was already drowning anyone that breathed it in as soon as the shift occurred. Our natural body heat... as if some killer design of nature, the mammals fatal flaw they'll call it. The steam condensed in our lungs back into the water we drank every day; hell, it's one of the only ways we can get water anymore is from those poor saps' chests. Just like this, at least four or five million people are dead, and not even a day has passed. Survivors in the cities board what they can and try to prevent leaks from allowing steam inside. They use SCUBA gear and other apparatuses to travel outside of safe zones, and groups begin forming and falling of all types.
We are to be one, (or more!?) of said groups.
I was looking to a more, feeble attempt at extreme survival horror at first, before we die haplessly when an octopus creeping in the sewers inks our whole team when we're trying to get away from piranha or something. (NOT this exactly, but you get the picture?) This is mostly because I'm a terrible survivor and group leader, which is probably why I want to find people to play roles, I need to see simulations of this world to get SOME ideas of what it would actually be like, eh?
I was also wondering how I would know exactly when the power and water started to shut off, or if there is any untainted water left in the pipes at all.
I don't know, this might interest you.
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Also, I'll allow some realistic prehistoric sea monsters in this like Helicoprion and Leviathan, you know?
Dwellers, too deep for us to find before, but they got to go with the flow too, to survive.
I also didn't mention raiding and banditry is definitely accepted in the context of the game.
Think The Road meets The Myst but with fish instead of extra-dimensional beings.