A place for theories about Oxygen Not Included.
You are an AI.
The player is an artificial intelligence tasked with managing this new colony. You can see further than the dupes (scanning, perhaps), initiate research into new tech, and you design and manage the base via programmed commands for the duplicants to follow.
The scale of the game is wrong.
Duplicants are actually a few centimeters tall, and all the other quantities in the game are scaled to match. A tiny size like that would help explain the strange water physics.
Kind of confirmed? Ingame duplicants weight exactly 1KG, and some of the new lore seems to point in this direction.
Some of the recovered Gravitas data mentions that the "test subjects" are 42cm tall.
The duplicants are part of an experiment.
Some Mad Scientist
-type organization has placed Duplicant Printers in several asteroids and is covertly monitoring them to see how they cope with the situation and what survival strategies seem to work the best.
The World Ended.
There is a cracked world in the background. It matches records that suggest this is your planet. Gravitas files mention an imminent apocalypse. Therefore: the world ended, and you are all that's left; an automated colony development system that activated while buried deep within fragments of the world cast off into space.
Earth is implied to have been destroyed by as unscrupulous Mega-Corp
screwing around with the fabric of spacetime. A planet riven to flinders while at the same time still habitable sounds like something a company that can turn off entropy