This is design is based on an ATtiny13a writing white noise to 3 shift registers, driving LEDs. The code is like 6 lines.

Every LED is synchronously enabled with an independent 25% probability. The trick is the refresh rate is slightly higher than your eye can perceive, but not so much that the matrix is a blur. There should be six lit at the given rate, but you perceive 12 to be on.

The effect is eye-catching on a physiological level, with your brain not sure how to process it. You find your eyes drawn to it yet if you try you will find you will be unable to focus on any particular part of it.

The battery life is surprisingly good. I was expecting shift registers to consume more power than microcontrollers, but it seems not to be the case.

I tried to arrange the 24 leds in a way that sort of looks like reflectiosn off of his helmet.

While I almost always prefer to make badges that are organically reactive, I wanted to represent the helplessness and mechanicalness of the situation the character was in in this scene.