This fit the theme better than anything I've played so far this jam.
Pros: The text dialogue feels authentic. You can tell these people have a relationship with one another. The frequent interruptions and notifications of signing on/off is a really good touch and adds to the pacing. It's a short, get-in-get-out game. You really had a vision and you did what you could to live up to that vision in the most efficient way. I genuinely felt the dread building as I was talking to Chloe. You wrote Chloe well enough to be juuuust creepy enough to instill doubt, but not so inherently creepy that it would ruin the surprise, or make the ending a lot cheaper. I like to perceive the ending as a misunderstanding, just because the other side of the coin is too scary. That's really effective storytelling.
Cons: These are all minor complaints, because like I said, this experience is really effective. However, it is just that: an experience. There's not much in the way of character, story, or plot. With that, there's very little to criticize, but it also means there isn't that much depth. If I had to nitpick, I felt like all of the characters kind of felt the same to me -- although I do appreciate you giving them their own chat bubble color so it's easier to tell them apart. To that end, the only character that mattered other than you was Chloe. The other characters just felt like filler, which is fine, because like I said it felt authentic, but not the most engaging narrative in the world. I also was a bit lost on what type of chat program this was, which only briefly distracted me and is mostly a me problem.
I saw in the profile that this was your first game jam. All I can say is congratulations. You came out swinging. Nicely done.