The first dust effect was a square

Dust should make a pickaxe strike feel connected to the rock. The first version instead exposed the shape of the flat surfaces used to draw it: opaque squares appeared at the impact. A material input was connected incorrectly, so the effect lost the transparency that was meant to hide those edges.

Correcting that connection removed the obvious failure, but the next pass was too faint. Another adjustment brought the dust back into view, followed by small cosmetic flakes. The useful change was in how the impact read, without replacing the preferred pickaxe or changing what the strike rewarded.

The effect still needed visual improvement, but the sequence was revealing. The first fix made the dust render correctly. The next made it noticeable. Only then was it useful to judge whether the strike felt better. A tiny puff at the end of a swing had turned into several rounds of work.