People have already commented on the brightness, but I would like to point out the sound. The monsters are really pretty quiet, and their noises are short ranged, so I only notice them when I aggro them. This means that
1. they aren't keeping me on edge, as I just sorta trip over them, rather than knowing they're present, while trying to avoid them.
and 2. I can't tell where they are. Even when chasing I can barely hear them.
If the enemy audio was more useful, then the darkness would work better (it's still too extreme rn imo, though), as I could use the audio to tell what direction they're in, and avoid them that way, instead of seeing them.
This would also mean that I would have only vague knowledge of where they are, helping tension, and wouldn't need to look at them to have any clue what's happening (there isn't much "this thing is breathing down my neck, I've gotta bolt", since I could've left the thing behind ages ago, but have no idea.) As things are, I'm often completely blindsided when I get hit, as they are pretty much silent, then it's suddenly game over.
I also think the enemies' design makes the darkness a bigger problem, as they blend in really easily.
If you haven't, I recommend looking at/ playing The Forest as, while often overly bright (it is much more an action game), it makes very good use of enemy audio, and enemies are a little shiny (and usually pretty lightly coloured to boot), which makes them easier to make out as they're attacking you, even when you only have your short ranged lighter to see. (Alien Isolation also benefits from having the xenomorph be shiny.)