For the purpose of debate, there exist two separate planets.
Lunari is a lush, Earth-sized world orbiting a pale orange star. Vast emerald forests, shallow inland seas, and rolling grasslands cover most of its surface. There are no cities, roads, or advanced technologies. The inhabitants, live in small tribes of 20–50 individuals. They build woven shelters from giant reed-like plants and spend their days fishing, gathering fruits, crafting simple tools from stone and bone, and sharing stories around bioluminescent campfires.
Meanwhile, Vexis is a heavily industrialised megaworld orbiting a brilliant blue-white star. Almost every natural landscape has been replaced by towering arcologies, machine complexes, and continent-spanning cities. The original oceans exist only as regulated reservoirs beneath armored domes. Its inhabitants, live in a hyper-advanced civilisation where technology permeates every aspect of existence.