Whe we discussed the beta-version of our new design, I proposed to use the tree idea for badges as well. Badges should be nodes: gold badges are roots, silver badges inner nodes, bronze badges leaves.
Paweł ran with that. Zoomed in, these are the current badge icons:
For me, the metaphor does not work: I see control nobs rather than tree nodes: bronze is more "tuned up" than gold. Also, silver just visually looks like "more" than gold.
What do you think? Do you have other ideas?