Soldering... didn't go great for me. It's not the fault of the LEDs, I'm just not very experienced with components this small. I'll keep trying past the scope of this contest but for now I'll invite you to mock my attempts! Boxes of rotten tomatoes will be distributed shortly.
I'd like to thank Gough Lui for sharing an excellent video on soldering techniques for this kit! Check it out if you haven't already: https://www.youtube.com/watch?v=33HIijhpB6g&list=PLrY3-lLxuZfWh8_cyZcIyZ4jRthiEd6oG&index=14
My lack of working results is my own fault rather than not having a good example to follow. Just had a hard time getting the PCBs to stay steady enough as I was working. I think I really need a new work clamp to use. Looking forward to using the magnifying glass thing from the finisher prize.

Trusty Weller brand solder 0.5mm worked the best overall. 0.3mm was too finicky for me. Not that it made much difference in the final results though.

I've seen cleaner joints in footage of Chernobyl.

Second batch went better than the first, but not by much.

Forgive me, Element 14, for I have sinned...

Here lies LED #13, who rode a cloud of magic smoke across the RGB bridge on 11/02/2025. He was only one PWM cycle away from retirement.

Tried all the LEDs I managed to get fully soldered up with the Arduino and breadboard, but didn't get any light output from it. Need to spend more time practicing really. The Arduino Zero works fine with some other sample code so it doesn't seem to be anything faulty. Either my solder joints aren't sound, or I'm just frying the LEDs without realizing it. Neither would surprise me. Time will tell, but that's as far as I could get by today. My final project post will summarize the future direction I'd like to try taking this project before I commit too much time to trying to get the breadboard prototype working. Should be done later today.
tl;dr I am bad at soldering but want to get better. Happy to hear any advice.