"Never show the monster," horror film-makers, game-makers and other creepozoids have chanted, over the decades. The Well Is Not Empty wastes no time showing us the monster - one of the monsters, at least - and doesn't seem especially the worse for it. I mean, it's the worse, but in a good way.
Look, you can see the monster right there, hunkered up like a frightened puppy in the corner of the room. A scrawny little fellow with broken xylophone teeth and eyes that genuinely do make me think of the view from the bottom of a well. The monster is no threat, as long as you stay out of grabbing distance - and as long as the lights are on. The problem, as you've already guessed, is that the lights are unreliable. A lot of the ceiling bulbs in the open areas are set to a timer. Best make sure you're back behind the sturdy radiance of those construction lamps before the ticking stops.