how did ya cook this hard with your first map

I've played it for only 20 mintues so far, but I really like what you've done here! I've inspected the image files, but I can't figure out how you made the tree and other collisions without having those textures in the cus_tileset file. Does it have something to do with the ground layer using the black preset? Would you care to explain that so I could make more detailed maps in the future, such as yours?