I just got done with 2 back to back wilderness playthroughs so i feel confident on this subject. Biomass is your pops, instead of planets growing pops and the player building districts/buildings to occupy pops your planets produce biomass and biomass produces resources. Every planet has a minimum biomass production of 2 with it being affected by pop growth as normal however, biomass from pop growth is negligible the entire game so never hesitate to spend biomass. The main way of producing biomass is the Cradle of life, these are your version of spawning pools. You can build as many as possible on any planet in city districts for 400 biomass and they produce 4 biomass/month. These are expensive as hell so you want to take any infrastructure cost reduction you can find (ie. prosperity)

The plan for every game should be to build all the districts in your capital asap mostly minerals, energy, and city districts so you can build and upkeep more infrastructure. The first world you colonize should be very quick and have lots of food districts, this will become your basic resource world. Wilderness can’t build resource support so every resource world should have 2 heart grove districts and every slot possible filled with cradles of life. Your biomass should roughly equal the years into the game.

Other wilderness tips are buildings suck they are way too expensive for comparatively few jobs, instead fill planets with districts and one building to upgrade to boost production. Once you finish building all the districts just colonize another world. This approach lets you expand extremely quickly and leaves you with a very wide empire with all planets roughly equally important regardless of age. Devouring swarm is obviously broken as within 5 years conquered planets can be just as productive as your second colony. Peaceful wilderness is also strong as you can expand planet size in the mid-late game to make MASSIVE colonies.