Because Galaxy is a SpaceSim, there of course is going to be Planets, they don't do much apart from have a name, description and a biome. there are a variety of Biomes that are available:
- Icy World
These will all have benefits and... not-fits. for example Grasslands will be majority Farming so you can get loads of Farming goods and thing on them. then there are Cities where you can buy Tech you can't get anywhere else, like Tablets etc.
They will also eventually range in size, i don't think this will do much apart from aesthetics.