Level design
-The procedural gen of the maps is a good start but I found myself not being all that immersed. IMO well done backrooms architecture is similar to real world architecture but something's off. It reminds you of somebody's DIY house reno that went horribly wrong. Difficult to put your finger on exactly what is off, but at first glance your brain just knows somethings odd. Perhaps it's a lack of symmetry, whatever it is, it's difficult to describe, and if you can find a way to summarize it and then procedurally generate it you'll become powerful beyond measure.
I can tell your map is generated on some sort of grid reference, it shows in the uniform shape and size of the pitfalls. I believe this is where the immersion starts to faulter. Adding random odd values to create irregularities in the grid will likely help create the backrooms effect.
-I loved the single chair sitting alone in the middle of a big wide empty space, more elements like this! More strange things to stumble upon, things that have noclipped in from the outside world, perhaps very old objects to convey the idea that the backroom realm is everpresent and has existed alongside our world since time began...
Enemy/AI
-make the bacteria respond to player whistles so players can work together to distract or lure it away
-it should not be outrunnable forever, it's rate of movement should be such that it WILL catch you if you don't hide or have someone distract it away from you. Or, there could be a penalty for exhausting your character too much, a period where they must walk to catch their breathe which will likely lead to being killed.
-the bacteria, when spotting a player could pause for a split second, roar and charge in a very intimidating manor
-the bacteria and or the other living entities in the world could cause interference with the video camera, this could be a method by which players can detect its presence
mint sky
vernal vector