Deserts and forests are cool and all, but what about biomes & planets that aren’t like anything we’ve seen on Earth? Several things i thought of were large underground cave systems, bioluminescence, and planets full of rare resources.
Large cave systems: Immaculate caves that act as the world map. Perhaps the surface of the planet is uninhabitable, giving a reason for cave only life(?). metals would be easier to get, and agriculture would be difficult; unless there are lots of mushrooms and plants that don’t require sun.
Bioluminescence: Everything’s glowing, plants, animals, everything. maybe the planets have long nights and short days(?). Biomes could have variants and colors. Cant think of anything else for this one, I just thought it would look really cool.
Rare resource planets: A planet full of crystals, minerals, metals and anything else just laying around for someone to take. Benefits to this could be early civilization or faster progression through society stages(?). Drawback would be higher chance of an alien invasion and other species reaching society stages quickly too.
anyway, those were just some ideas I had. I’m no scientist so I don’t know if these are even possible or scientifically accurate.