Major UI/Gameplay Update

Updates/New:
Added: Mouse Click playability.
Added: Right-Click to restart game.
Added: Mountains in the distance.
Added: Volume Button & Volume Button UI.
Added: Animation to "Restart key text 'r/right-click'" & Flappy Duck Title Text.

Changed: "Customize Button" UI.
Changed: Restart key text 'r' to Restart key text 'r/right-click'.
Changed: Old "Sun" Sprite to New "Sun" Sprite.
Changed: Old "Background" Sprite to New "Background" Sprite.