My.kv

<Invader>:
    size: [100, 100]
    canvas:
        Rectangle:
            pos: self.pos
            size: self.size
            source: self.src
<Planet>:
    size: [100, 100]
    canvas:
        Rectangle:
            pos: self.pos
            size: self.size
            source: self.src
<Bullet>:

    canvas:
        Rectangle:
            pos: self.pos
            size: self.size
            source: self.src

<GameWidget>:
    player: player_state
    canvas.before:
        Rectangle:
            size: self.size
            pos: self.pos
            texture: self.bg_texture
    canvas:
        Rectangle:
            size:10,self.height
    Label:
        font_size: 70
        center_x: root.width / 2
        top: root.top - (root.height / 2)
        text: root.go_string
        font_name: "Minecraft"
        color: 1,1,1,1
    Label:
        font_size: 70
        center_x: root.width / 2
        top: root.top - 200
        text: root.title_s
        font_name: "Minecraft"
        color: 1,1,1,1
    Label:
        font_size: 40
        center_x: root.width / 2
        top: root.top - (root.height - 200)
        text: root.hint_text
        font_name: "Minecraft"
        color: 1,1,1,1
    Label:
        font_size: 30
        pos: 150, root.top - 150
        text: "ESC - Exit\n\nC - Change ship"
        font_name: "Minecraft"
        color: 1,1,1,1
    Player:
        id: player_state

<Player>:
    id: player_state
    size: [100, 100]
    canvas:
        Rectangle:
            pos: self.pos
            size: self.size
            source: self.src