Baby continents form. Crustal recycling starts. Plate tectonics might also have become a thing. It's not a party without glamour, and the first diamonds are brought to the surface.
But, the big story is life... It's getting everywhere. There are stromatolites, and evidence of bacteria and archea. By the end of the era, cyanobacteria are producing large amounts of oxygen as a byproduct of photosynthesis. They are about to change the Earth forever.