Good, but has room for improvement
The ideas and plot were pretty fresh and interesting. I like the way Karissa's eyes are empty, since as a protagonist you're supposed to be relating to her, but the way she looks makes her seem a bit different.
The timeline was a little difficult to follow, though. Even though there was the "3 days earlier" thing, it was kind of impossible to tell what was a flashback and what was actually happening in the present.
I also spotted some contradictions. She talks about only having one friend and says, "Why would anyone want more than one friend?" and then she calls the worms her 'friends', implying that she does have more than one. I think 'guardians' or 'protectors' would've been a better word for them.
Also, for a town where it always rains, it sure doesn't rain a lot (didn't rain in some scenes). It kind of breaks the atmosphere that was set up at the beginning.
I'm looking forward to watching this and seeing how it progresses.