apply suggestions

- Replace the sprite with a solid black box when a storyboard requests it.
- Create a new storyboard instance and exclude the fail layer as well as strip all samples from it
- Do not attempt in creating the storyboard when it isn't needed

osu.Game/Graphics/Backgrounds/BeatmapBackgroundWithStoryboard.cs

@@ -1,10 +1,13 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Textures;
 using osu.Framework.Timing;
 using osu.Game.Beatmaps;
+using osu.Game.Storyboards;
 using osu.Game.Storyboards.Drawables;
 
 namespace osu.Game.Graphics.Backgrounds
@@ -19,16 +22,23 @@ namespace osu.Game.Graphics.Backgrounds
         [BackgroundDependencyLoader]
         private void load()
         {
-            LoadComponentAsync(new DrawableStoryboard(Beatmap.Storyboard)
-                {
-                    Clock = new InterpolatingFramedClock(Beatmap.Track),
-                },
-                loaded =>
-                {
-                    AddInternal(loaded);
-                    if (Beatmap.Storyboard.ReplacesBackground)
-                        Sprite.FadeOut(300, Easing.OutQuint);
-                });
+            if (!Beatmap.Storyboard.HasDrawable)
+                return;
+
+            var storyboard = new Storyboard { BeatmapInfo = Beatmap.BeatmapInfo };
+            foreach (var layer in storyboard.Layers)
+            {
+                if (layer.Name != "Fail")
+                    layer.Elements = Beatmap.Storyboard.GetLayer(layer.Name).Elements.Where(e => !(e is StoryboardSampleInfo)).ToList();
+            }
+
+            if (storyboard.ReplacesBackground)
+            {
+                Sprite.Texture = Texture.WhitePixel;
+                Sprite.Colour = Colour4.Black;
+            }
+
+            LoadComponentAsync(new DrawableStoryboard(storyboard) { Clock = new InterpolatingFramedClock(Beatmap.Track) }, AddInternal);
         }
     }
 }