main.py

from kivy.app import App
from kivy.lang import Builder

Builder.load_string(
'''
#:import Image kivy.core.image.Image
#:import time time.time
Widget:
    texture_1: Image('Sky_back_layer.png').texture
    texture_2: Image('Vegetation_(middle_layer).png').texture
    texture_2: Image('Ground_(front_layer).png').texture

    texture_1.wrap: 'repeat'
    texture_2.wrap: 'repeat'
    texture_3.wrap: 'repeat'

    texture_1.uvpos: time() * 0.001, 0
    texture_2.uvpos: time() * 0.01, 0
    texture_3.uvpos: time() * 0.1, 0

    canvas:
        Rectangle:
            pos: self.pos
            size: self.size
            texture: self.texture_1
        Rectangle:
            pos: self.pos
            size: self.size
            texture: self.texture_1
        Rectangle:
            pos: self.pos
            size: self.size
            texture: self.texture_1
''')


class MyApp(App):
    pass


if __name__ == '__main__':
    MyApp().run()