Currently, the game is unplayable without trees. You need to collect 20 wood for your first greenhouse. Especially with the hidden tech tree, this is very annoying. Playing without trees and rocks is allowed in the settings and usually possible. Ultracube only needs a few trees to build the first greenhouse and can then produce them.
The suggestion is to add 20 wood into your starting inventory or the ultracube chest. This would make the game playable without trees.
