This was really well done! I love the art direction of Kadie and the radio tower, as well as the excellent sound design choices!
I will say that I had some technical difficulties while playing; after loading a saved game Kadie would move but the background would remain static. This also occurred after going into the sound settings. It's a shame because I would have loved to check out the other endings, but that will mean starting the whole game from the beginning for me.
Still, I'm happy with the ending I got. It really made me think about how impermanent our connections are with people, whether it's with people we know physically or our online communities. I've encountered a few instances of people who I've admired vanishing online one day due to circumstances beyond my control, and I wish I had taken the chance to reach out to them and tell them how much I love what they have created. I try to make it a habit now of telling people how much they mean to me, because I know that there's a chance I won't always be able to. So while I feel sad that Kadie and Signal can't communicate with each other anymore, I am happy they got the chance to tell each other how important they were while they still could. I think that's a privilege we don't appreciate until it's too late.
Overall, this was a great little labour of love. Hopefully a future update can fix the issues with saves, because I'd love to re-play it again.