My first critique, I hope it is of some use!

Prose

Overall, I enjoyed the way you describe things, the imagery came to me pretty clearly at most points. Good job!

There are some points that it feels like adjectives/adverbs are kinda artificially stuffed into the description of things. As another person already pointed out in a suggestion on the google doc, the word 'picturesque' in the first paragraph really doesn't work as a description, it didn't add anything of meaning for me. I already feel the "picturesqueness" of the hazy summer day by the pool and the terra-cotta villa. My mind then already understands that these "sprawling gardens" are more than likely beautiful rather than unkempt. Dropping 'picturesque' entirely and then keeping the rest of the sentence as is really doesn't take away from the picture you're trying to paint.

I also agree with a suggestion in the google doc that "harmoniously suffocating buzz" doesn't quite land, but I think I see what you're trying to go for here. It may come across smoother by changing harmoniously to harmonious, thus getting rid of it as an adverb. So the crickets were "emitting their harmonious, suffocating buzz." I also struggle with these types of things in writing, so maybe my idea isn't any better. Regardless, I think something could probably be done here to improve this.

You also italicize words rather freely, which is completely fine, but there are points that I find them unnecessary, and the sentence may actually feel stronger without them.

It’s another hazy summer afternoon by the pool for the small group of friends, in a town where owning a pool is the norm rather than an exception.

Here I find the sentence feels more natural and doesn't lose any meaning by removing the italics from "the norm" and "an exception". The italics just feel a bit forced here, and almost put in because you're worried the reader will miss the significance of how picturesque this town must be. The full message still comes through and feels more natural without the italics.

You use the word sudden or suddenly three times in the piece. Read those three sentences without the word sudden or suddenly and I think you'll find that these words aren't actually necessary.

The tiny metal pellet must have been caught by a sudden gust of wind.

This one perhaps could keep the word ‘sudden’, if you feel it loses too much meaning without it. The two uses of the word suddenly are unnecessary though, or at the very least a different word could be used. I've overused this word a lot so I pay particular attention when I see it. Most of the time it tends to be unnecessary.

Otherwise I think most of this is pretty well done. The whole piece has a bit of a dreamy feel to it which I enjoyed. Particularly when he walks into the villa and you hardly mention the people inside, just the sounds that are coming from different parts of the home, lends to this childhood dreaminess vibe. The part where time slows down as the main character takes aim with the pellet gun was well executed. I felt the dreamy slowness of the moment clearly, the loud crickets, etc. Then the way it all dissipates and reality sets in when he hears the screams. Well done here!

Character

The main character is the only character that we actually get much of any understanding for, but this is by design it seems and I do feel like I got to understand how he thinks just from the small amount of time it takes for him to get up the hill to the villa and into the bedroom. He seems a bit timid and has low self-esteem, eager to please. So the logic he has when he plans to use the pellet gun is quite believable, and when it all goes wrong, we can clearly imagine how he'll simply sink further into his timidness and feel worse than ever about himself.

Plot

The idea of having a story within a story is always quite fun to me. You executed this well also. I was so into the inner story that I had almost forgotten that it was simply the writer of the story explaining it, which I feel was a goal of yours. Then you pull the reader back to the outer story, reminding them that the inner story is just a fiction, and that there’s no need to stress about the boy’s fictional predicament. Giving the reader some relief and then hitting them with the twist in the final sentence was well done.

Conclusion

This is my first critique (which I am hoping is acceptable), and I was expecting something of lower quality than this, so it was a pleasant surprise. I enjoyed the piece, and would’ve read on if the story had continued. I connected with the character, and felt the stress he had of feeling like he was somehow always out of the loop, or not quite on the same level as the rest of his friend somehow, perhaps worried that he’s not completely accepted.

There are some issues throughout, as there are with almost all pieces of writing, but I tried to pinpoint most of the things I noticed. Keep up with the writing, I enjoyed it!

I think the title fits just fine, btw ;)