fix: make sq background color consisent (remove Z-axis overlap)

src/game.rs

@@ -141,7 +141,7 @@ fn spawn_square_at (commands: &mut Commands, level: u8, position: usize, asset_s
             ..Default::default()
         },
         transform: Transform {
-            translation: Vec3::new(x, y, 0.0),
+            translation: Vec3::new(x, y, 0.2),
             scale: Vec3::new(148.0, 148.0, 1.0),
             ..Default::default()
         },