My project is going slowly, but I finished building and painting the feature wall in my son's new bedroom. Now I just need to install and program the LED strip along the top!
My wife got the idea to do a geometric mountain feature wall from Pinterest. I am really happy with this outcome and feel I did a better job than the influencer DIYers who did similar projects that inspired this one. Giving the mountains a 36° slope to match the roof line was a pain in the butt, but the end effect was worth it.
Thanks to everyone here who helps with thoughts on patching wall cracks and LED lighting methods. I'll share photos of the full room once it is complete.
Edit to add: The wall is actually a mildly dark blue-green. Between bad natural light and my phone's camera's limitations, this is the best I can get for now. The mountains are not actually black.
I will share more once the whole build is done. If you look back a month or so in this sub, you can see the notes page there I planned my layout for the mountains. I think the room will be finished in a week or so, and there will be plenty of pictures then.