Lovely core idea for the setting, with a solid set of rooms at the location to explore.
The game design approach is effective, sticking to what works in the existing mosh modules, and adding a new dimension with the lightsource aspect.
I think it might be good if the photoreceptor grafts gave some benefit, as well as incurred new problems for the players. That way it could be a worthwhile trade and an interesting story point for an ongoing character? Something like having the grafts give advantage in well-lit combat etc etc.
Overall I like the stark b+w approach as it looks neat and is easily readable, but I would really appreciate more visual material for the walking plant creatures. Players are going to be very interested in them, and a picture to show might really set the mood.