I'm always glad when I see an arachnophobia mode in a game :) Also the content warnings in the page, it shows that you are considerate regarding the players!
Some of the tips I would share is that I miss a mouse sensibility option, my mouse was jumping all over the place :P But I understand if its not a top priority since the first person part of the gameplay is mostly for story purpuses.
Also I'm on opera GX and the game was working fine most of the time, sometimes there was a small freeze when bouncing on a spider so there may be a technical issue in the collisions or something else there.
Overall I like how you are depicting depression here and I think that introducing gameplay elements to depict intrusive thoughs is a very original way to blend in a narrative element.