Stocking stuffers like this 555/4017 LED strobe kit almost always present interesting challenges/learning opportunities.
Julian Ilett had fun re-wiring the same kit.
For myself, I found out the PCB appeared to have the supplied transistors connected upside down,
and some adjustments to the resistor values yielded a better effect.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub