feat: adjusted SlingShot size

lib/game/components/sling_shot.dart

@@ -33,18 +33,19 @@ class SlingShot extends BodyComponent {
   /// left.
   final BoardSide _side;
 
-  List<FixtureDef> _createFixtureDefs() {
+  /// The size of the [SlingShot] body.
-    final fixtures = <FixtureDef>[];
-
   // TODO(alestiago): Use size from PositionedBodyComponent instead,
   // once a sprite is given.
-    final size = Vector2(10, 10);
+  static final Vector2 size = Vector2(6, 8);
+
+  List<FixtureDef> _createFixtureDefs() {
+    final fixtures = <FixtureDef>[];
 
     // TODO(alestiago): This magic number can be deduced by specifying the
     // angle and using polar coordinate system to place the bottom right
     // vertex.
     // Something as: y = -size.y * math.cos(angle)
-    const additionalIncrement = 2;
+    const additionalIncrement = 3;
     final triangleVertices = _side.isLeft
         ? [
             Vector2(0, 0),
@@ -78,7 +79,7 @@ class SlingShot extends BodyComponent {
       );
     // TODO(alestiago): Play with restitution value once game is bundled.
     final kickerFixtureDef = FixtureDef(kicker)
-      ..restitution = 20.0
+      ..restitution = 10.0
       ..friction = 0;
     fixtures.add(kickerFixtureDef);