The alley was dark, cold, and damp. Trash and debris littered the ground making it hard to walk. My nostrils were inundated with the smells of garbage and excrement. The sickening, sweet smell of decay hung in the thick air. Oh, how I longed desperately to be out of this place.

Dim and scarce was the light casting vague shadows in my wake. Beady, black eyes watched as I moved through this horrid hell. These rats seemed unnaturally large. Keeping their distance, they stared at me, planning my demise. Their claws raked across the cobblestones as they moved, sending shivers down my spine.

Feeling light-headed, I reached out to support myself against the wall. It felt cold and slimy to the touch; much like the feel of a rotted corpse covered with ooze. My stomach threatened to empty itself of its contents.

-- I get that you're trying to create a mood, but the first sentence doesn't grab me. Most alleys in literature are cold, damp and scary. If it were brightly lit and strewn with rose pedals, I'd be more interested because that's unusual.

-- I know nothing about the viewpoint character except that he's in a dark alley, and I'm not sure what the conflict is. In some stories, you can get away with delaying one or the other. In flash fiction, both should probably be upfront and center simply because you have so few words to work with.

I don't know anything about Lovecraft's style, but it seems a bit stilted and remote. I would normally point this out as a problem, but I suspect this is actually the style you're trying to achieve.

I don't know the style you refer to, so I am not sure if you hit it on the head or missed completely. But, I think it has a good voice to it and describes a good scene.

However, for an opening it lacks much action. You have painted a great scene here, and I wonder why your MC would be here if they hate it so much. But, I felt like you MC wasn't doing anything but standing there taking it the disgusting scenery.

Also, please note that I am only commenting on these first 13 lines. It is quite possible that your work as a whole has more of the tell tale signs of the Lovecraftian style of writing.

There are some lines that I felt redundant - such as "The alley was dark, cold, and damp." While there were other lines that I found to be a lot more evocative and created a clearer sense of setting, such as - "The sickening, sweet smell of decay hung in the thick air" and "Their claws raked across the cobblestones as they moved, sending shivers down my spine."

So, I guess this begs the question, how do you make your style more like Lovecraft's? The best way I can describe his style is that from the very first sentence to the last there is a very palpable and oppressive sense of man's insignificance before the cosmic unknown. There is an ever-growing sense of horror which is both oppressive and insanity inducing. Therefore, Lovecraft's prose (at least to me) carries the reader along with a sense of urgency and restlessness all the while assaulting the senses with the incongruous and grotesque.

Finally, my last piece of advice is simply write it your way. Lovecraft was Lovecraft. Certainly feel free to borrow themes, but I am sure readers will come to appreciate Drock0211's style and voice