Some objects have several variants in the file, like trees, rocks, plants, clouds. They also have material variants. Most are textured based, but the material nodes setup have color vartiations to add or remove moss on the rocks by example, and make saturation variations when needed. Objects that requiered UVs have their UVs ready, other materials rely on generated textures. Geometry is rather high poly count, and materials are well details. Other assets have a more stylized or simplified look and will look better once inserted in a surrounding environment.