You haven't been able to sleep well for a while. Maybe tonight will be different...
It's okay. Not bad, not great. It's passable. I liked the "Ending".
Be more adventurous with level design on a time budget. Would have been cool, for example, had this been a vertical level with stairs and offshoot rooms, rather than horizontal and plain.
Light entities are your friend, so is fog. Try to exploit them next time.
For a 24 hour custom story, it's not horrible and you're on the right track. Try to be more ambitious with your next work and take it to a proper custom story, one that takes a few months to make. I think you'd do much better.