I decided to "just quickly play around to see if I can make a mushroom cloud" prior to beginning work on a "proper" animation, then this started to look good and kind of took over! Most of the time spent here was fine tuning: figuring out how to animate the blast without distorting it too much, animating the camera, putting some kind of scenery in, and then squeezing all these tweaks into 512 bytes. But the main thing I like is the big mushroom cloud, and that was found by luck on the third attempt! Ain't I a jammy git?