Make playfield dark, not light. No masking either.

osu.Game/GameModes/Play/Osu/OsuPlayfield.cs

@@ -6,6 +6,7 @@ using osu.Framework.Graphics.Containers;
 using OpenTK;
 using osu.Framework;
 using osu.Framework.Graphics.Sprites;
+using OpenTK.Graphics;
 
 namespace osu.Game.GameModes.Play.Osu
 {
@@ -28,6 +29,7 @@ namespace osu.Game.GameModes.Play.Osu
                 Anchor = Anchor.Centre,
                 Origin = Anchor.Centre,
                 RelativeSizeAxes = Axes.Both,
+                Colour = Color4.Black,
                 Alpha = 0.5f
             });
         }

osu.Game/GameModes/Play/Playfield.cs

@@ -8,11 +8,5 @@ namespace osu.Game.GameModes.Play
 {
     public class Playfield : Container
     {
-        public override void Load(BaseGame game)
-        {
-            base.Load(game);
-
-            Masking = true;
-        }
     }
 }