Ok, so my first impressions aren't great. The format is large paragraphs of text, which makes reading a little difficult. You don't have a lot of dialogue, so you can't break it up like that. If I could make a suggestion, it would be to break the blocks up into smaller parts, maybe depending on the content? That would certainly make it easier to read.
The other main concern is how overly descriptive everything is. I don't mean you have long winding paragraphs of scene setting like Tolkien or G.R.R. Martin, but instead almost every word gets an adjective of some kind. Now I know, the more descriptions the better right? But in this case, since almost every noun gets an adjective, it feels rather overloaded. At least for me, it was a little distracting. I think the issue I listed above about formatting would help here, as it would help draw attention from all these singular adjectives in a large block of text. Let me give an example.
The flashlight barely reveals what looks to be the start of a ladder. An especially rusted ladder at that, tattered nearly entirely by a brownish corrosion.
In this instance, you take an entire extra sentence to describe the ladder, but not in the same sentence it's introduced. You do this again in another part of the same paragraph.
If that wasn't worrying enough, its deep crack had echoed within the hatch. This wasn't the echo you might hear in a theatre. This was a deep, hollow, haunting echo that kept reverberating for what I felt was 20 seconds.
You take three sentences to describe a singular echo. Now, you aren't required to not describe things, especially if it's important to the story, but it feels so overloaded here its difficult to get through. If I could reword that section, I might do it in my own style, which is like this:
If that wasn't worrying enough, the crack began to reverberate within the hatch; a deep haunting echo that lingered for about half a minute.
I'll use this to transition into the other aspect of your tale, which is prose. I'll apologize in advance, because prose is something I still struggle with, so my ability to describe it is limited. Your style here seems to border between stream of consciousness and traditional first person. I would suggest sticking to one or the other, because otherwise the tale feels disjointed.
Other than that, the prose itself is a little plain. Your usage of adjectives feeds into this, it's a little predictable: Article, adjective, noun, action/more adjective. I would suggest trying vary your sentences, at least if you are using traditional first person. If using stream of consciousness, go nuts.
You also alternate between present and past tense. I'd suggest sticking with one just to make it easier for yourself and the reader.
Ultimately though, I think the majority of the problems here stem from the format. Chop these paragraphs up, and let them work for you. Build tension by introducing concepts and events in the next paragraph.