Obviously it could do with an edit, as typo's always make a story harder to read. And I'd say it's a little too conventional in its story matter - these are roads well trod. But it's still more positive than negative, though you do need to work out how to give it a punchier ending. (Having the silver being suggest that some humans may survive for a while longer by going underground, say - or even have one of them impulsively ask a question "what will become of us?" - then they have the dilemma of taking this answer or not back to the Elder...).

I'd suggest "Gemma" is too anglicised a name for your protagonist, and an earlier foreshadowing that fish are getting smaller, perhaps, also might help.

Keep at it though, and glad you had fun!

Liam

Lots of detail but i kept asking myself why should i care? There sould have been a life or death issue at hand to give the plot more conflict and a sense of urgency.

I couldn't resist reading by an author who uses the name of one of my favorite Gaiman books.

The first paragraph was prologue-y. In fact, I believe you could probably cut out almost everything before the journey, and actually focus on the journey itself, while establishing the important parts of the backstory along the way. For instance, you could establish that they are on "the trial" and that they each have a question they're supposed to ask the silver being. We don't have to see that conversation real-time.

In the same vein, focusing on the journey could make "the trial" seem like an actual trial. It really didn't; you actually seemed to go out of your way to show how relatively easy the journey seemed to be. You should instead be heaping on conflict. Torture your characters and put them in constant peril. Otherwise, I really don't have any reason to care about them.

There were some areas that seemed a little inconsistent. For a society you tried to establish as being very alien, the dialogue at times seemed odd and modern, as if you couldn't decide between trying to lure us away or toward believing them to be human descendents. IE, should I believe that something that uses a unit of time called a "yearling" and has gigantic eyes would still use smiling as a way to express happiness, when most animal species (including those closely related to humans) use smiling for other reasons?

I hope this doesn't come off as completely negative, because even though I felt it could use some work, I enjoyed it well enough. I thought it was a good concept that didn't quite get the attention it needed, as it requires some misdirection and cleverness to ensure the ending has any punch, so if you only dedicated three hours to it, then you shouldn't feel bad that you didn't nail it on the first try. I think if you sat and spent a few more hours, or even rewrote this from scratch without trying to hit such an urgent deadline, you could come out with a much more solid piece.