Many tweaks thanks to IAmActuallyCthulhu

Also change apostrophes to double quotes and update C# projects

mono/pong/Logic/CeilingFloor.cs

@@ -0,0 +1,15 @@
+using Godot;
+
+public class CeilingFloor : Area2D
+{
+    [Export]
+    private int _bounceDirection = 1;
+
+    public void OnAreaEntered(Area2D area)
+    {
+        if (area is Ball ball)
+        {
+            ball.direction = (ball.direction + new Vector2(0, _bounceDirection)).Normalized();
+        }
+    }
+}