The black and white line art style is very clean, though sometimes it was hard to tell when I could be detected by enemies. It was also hard to tell solid walls apart from background elements you could walk past. Just a small amount of color could be used to clarify this, kind of like how the doctor glows red when she spots you.
I like how the other rats seem to be on the doctor's side--usually in stories like this, the rats team up in some way. It's a neat subversion of the "experiment subject escaping containment" trope...
I also like the idea that the way you hide from rats and the way you hide from the doctor/humans is different, though I think you could push that idea even further. To exemplify the difference between the two enemy scales, maybe you could actually fight the rats in some way. Lean more into the action/combat when in darkness, and platforming/movement/stealth when in the light.