diff --git a/lib/game/components/ball.dart b/lib/game/components/ball.dart
index e166bd40..6540caee 100644
--- a/lib/game/components/ball.dart
+++ b/lib/game/components/ball.dart
@@ -6,17 +6,17 @@ import 'package:pinball/game/game.dart';
 /// A solid, [BodyType.dynamic] sphere that rolls and bounces along the
 /// [PinballGame].
 /// {@endtemplate}
-class Ball extends BodyComponent<PinballGame> with Layer {
+class Ball extends BodyComponent<PinballGame> with Layered {
   /// {@macro ball}
   Ball({
     required Vector2 position,
-    RampType? layer,
+    Layer? layer,
   })  : _position = position,
-        _layer = layer ?? RampType.all;
+        _layer = layer ?? Layer.all;
 
   /// The initial position of the [Ball] body.
   final Vector2 _position;
-  final RampType _layer;
+  final Layer _layer;
 
   /// The size of the [Ball]
   final Vector2 size = Vector2.all(2);
diff --git a/lib/game/components/components.dart b/lib/game/components/components.dart
index 2cfc3cd4..918112d9 100644
--- a/lib/game/components/components.dart
+++ b/lib/game/components/components.dart
@@ -2,10 +2,10 @@ export 'ball.dart';
 export 'baseboard.dart';
 export 'board_side.dart';
 export 'bonus_word.dart';
-export 'crossing_ramp.dart';
 export 'flipper.dart';
 export 'jetpack_ramp.dart';
 export 'joint_anchor.dart';
+export 'layer.dart';
 export 'pathway.dart';
 export 'plunger.dart';
 export 'round_bumper.dart';
diff --git a/lib/game/components/jetpack_ramp.dart b/lib/game/components/jetpack_ramp.dart
index ed08e540..9039fe3a 100644
--- a/lib/game/components/jetpack_ramp.dart
+++ b/lib/game/components/jetpack_ramp.dart
@@ -35,7 +35,7 @@ class JetpackRamp extends Component with HasGameRef<PinballGame> {
         radius: _radius,
         angle: _angle,
         rotation: _rotation,
-        categoryBits: RampType.jetpack.maskBits,
+        layer: Layer.jetpack,
       ),
     );
 
@@ -59,9 +59,7 @@ class JetpackRamp extends Component with HasGameRef<PinballGame> {
 }
 
 /// {@template jetpack_ramp_opening}
-/// Implementation of [RampOpening] for sensors in [JetpackRamp].
-///
-/// [RampOpening] with [RampType.jetpack] to filter [Ball]s collisions
+/// [RampOpening] with [Layer.jetpack] to filter [Ball] collisions
 /// inside [JetpackRamp].
 /// {@endtemplate}
 class JetpackRampOpening extends RampOpening {
@@ -74,7 +72,7 @@ class JetpackRampOpening extends RampOpening {
         _orientation = orientation,
         super(
           position: position,
-          layer: RampType.jetpack,
+          layer: Layer.jetpack,
         );
 
   /// Orientation of entrance/exit of [JetpackRamp] where
@@ -102,8 +100,8 @@ class JetpackRampOpening extends RampOpening {
 }
 
 /// {@template jetpack_ramp_opening_ball_contact_callback}
-/// Implementation of [RampOpeningBallContactCallback] to listen when a [Ball]
-/// gets into a [JetpackRampOpening].
+/// Detects when a [Ball] enters or exits the [JetpackRamp] through a
+/// [JetpackRampOpening].
 /// {@endtemplate}
 class JetpackRampOpeningBallContactCallback
     extends RampOpeningBallContactCallback<JetpackRampOpening> {
diff --git a/lib/game/components/crossing_ramp.dart b/lib/game/components/layer.dart
similarity index 55%
rename from lib/game/components/crossing_ramp.dart
rename to lib/game/components/layer.dart
index 65a5db43..558ad9dd 100644
--- a/lib/game/components/crossing_ramp.dart
+++ b/lib/game/components/layer.dart
@@ -3,15 +3,16 @@
 import 'package:flame_forge2d/flame_forge2d.dart';
 import 'package:pinball/game/game.dart';
 
-/// {@template layer}
-/// Modifies maskBits of [BodyComponent] for collisions.
+/// Modifies maskBits of [BodyComponent] to control what other bodies it can
+/// have physical interactions with.
 ///
-/// Changes the [Filter] data for category and maskBits of
-/// the [BodyComponent] to collide with other objects of
-/// same bits and ignore others.
+/// Changes the [Filter] data for category and maskBits of the [BodyComponent]
+/// so it will only collide with bodies having the same bit value and ignore
+/// bodies with a different bit value.
 /// {@endtemplate}
-mixin Layer on BodyComponent<PinballGame> {
-  void setLayer(RampType layer) {
+mixin Layered<T extends Forge2DGame> on BodyComponent<T> {
+  /// Sets [Filter] category and mask bits for the [BodyComponent]
+  set layer(Layer layer) {
     for (final fixture in body.fixtures) {
       fixture
         ..filterData.categoryBits = layer.maskBits
@@ -20,21 +21,11 @@ mixin Layer on BodyComponent<PinballGame> {
   }
 }
 
-/// Indicates a orientation of the ramp entrance/exit.
+/// Indicates the type of a layer.
 ///
-/// Used to know if ramps are looking up or down of the board.
-enum RampOrientation {
-  /// Looking up of the board.
-  up,
-
-  /// Looking down of the board.
-  down,
-}
-
-/// Indicates a type of the ramp.
-///
-/// Used to set the maskBits of the ramp to determine their possible collisions.
-enum RampType {
+/// Each layer type is associated with a maskBits value to define possible
+/// collisions within that plane.
+enum Layer {
   /// Collide with all elements.
   all,
 
@@ -45,37 +36,43 @@ enum RampType {
   sparky,
 }
 
-/// Utility methods for [RampType].
-extension RampTypeX on RampType {
-  /// Mask of bits for each [RampType].
-  int get maskBits => _getRampMaskBits(this);
-
-  /// Mask of bits for each [RampType].
-  int _getRampMaskBits(RampType type) {
-    switch (type) {
-      case RampType.all:
-        return Filter().maskBits;
-      case RampType.jetpack:
-        return 0x010;
-      case RampType.sparky:
+/// Utility methods for [Layer].
+extension LayerX on Layer {
+  /// Mask of bits for each [Layer].
+  int get maskBits {
+    switch (this) {
+      case Layer.all:
+        return 0xFFFF;
+      case Layer.jetpack:
+        return 0x0010;
+      case Layer.sparky:
         return 0x0100;
     }
   }
 }
 
+/// Indicates the orientation of a ramp entrance/exit.
+///
+/// Used to know if a ramp is facing up or down on the board.
+enum RampOrientation {
+  /// Facing up on the board.
+  up,
+
+  /// Facing down on the board.
+  down,
+}
+
 /// {@template ramp_opening}
 /// [BodyComponent] located at the entrance and exit of a ramp.
 ///
 /// [RampOpeningBallContactCallback] detects when a [Ball] passes
 /// through this opening.
-/// Collisions with [RampOpening] are listened
-/// by [RampOpeningBallContactCallback].
 /// {@endtemplate}
 abstract class RampOpening extends BodyComponent {
   /// {@macro ramp_opening}
   RampOpening({
     required Vector2 position,
-    required RampType layer,
+    required Layer layer,
   })  : _position = position,
         _layer = layer {
     // TODO(ruialonso): remove paint color for BodyComponent.
@@ -83,10 +80,10 @@ abstract class RampOpening extends BodyComponent {
   }
 
   final Vector2 _position;
-  final RampType _layer;
+  final Layer _layer;
 
   /// Mask of category bits for collision with [RampOpening]
-  RampType get layer => _layer;
+  Layer get layer => _layer;
 
   /// The [Shape] of the [RampOpening]
   Shape get shape;
@@ -112,51 +109,52 @@ abstract class RampOpening extends BodyComponent {
 /// {@template ramp_opening_ball_contact_callback}
 /// Detects when a [Ball] enters or exits a [Pathway] ramp through a
 /// [RampOpening].
-/// Modifies [Ball]'s maskBits while is inside the ramp. When [Ball] exits,
+///
+/// Modifies [Ball]'s maskBits while it is inside the ramp. When [Ball] exits,
 /// sets maskBits to collide with all elements.
 /// {@endtemplate}
-abstract class RampOpeningBallContactCallback<Area extends RampOpening>
-    extends ContactCallback<Ball, Area> {
+abstract class RampOpeningBallContactCallback<Opening extends RampOpening>
+    extends ContactCallback<Ball, Opening> {
   /// Collection of balls inside ramp pathway.
   Set get ballsInside;
 
   @override
   void begin(
     Ball ball,
-    Area area,
+    Opening opening,
     Contact _,
   ) {
-    RampType layer;
+    Layer layer;
     if (!ballsInside.contains(ball)) {
-      layer = area.layer;
+      layer = opening.layer;
       ballsInside.add(ball);
     } else {
-      layer = RampType.all;
+      layer = Layer.all;
       ballsInside.remove(ball);
     }
 
-    ball.setLayer(layer);
+    ball.layer = layer;
   }
 
   @override
-  void end(Ball ball, Area area, Contact contact) {
-    RampType? layer;
+  void end(Ball ball, Opening opening, Contact contact) {
+    Layer? layer;
 
-    switch (area.orientation) {
+    switch (opening.orientation) {
       case RampOrientation.up:
-        if (ball.body.position.y > area._position.y) {
-          layer = RampType.all;
+        if (ball.body.position.y > opening._position.y) {
+          layer = Layer.all;
         }
         break;
       case RampOrientation.down:
-        if (ball.body.position.y < area._position.y) {
-          layer = RampType.all;
+        if (ball.body.position.y < opening._position.y) {
+          layer = Layer.all;
         }
         break;
     }
 
     if (layer != null) {
-      ball.setLayer(layer);
+      ball.layer = layer;
     }
   }
 }
diff --git a/lib/game/components/pathway.dart b/lib/game/components/pathway.dart
index 8546a9ed..5e4cadf6 100644
--- a/lib/game/components/pathway.dart
+++ b/lib/game/components/pathway.dart
@@ -2,6 +2,7 @@ import 'package:flame/extensions.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
 import 'package:flutter/material.dart';
 import 'package:geometry/geometry.dart';
+import 'package:pinball/game/components/components.dart';
 
 /// {@template pathway}
 /// [Pathway] creates lines of various shapes.
@@ -14,10 +15,10 @@ class Pathway extends BodyComponent {
     Color? color,
     required Vector2 position,
     required List<List<Vector2>> paths,
-    int? categoryBits,
+    Layer? layer,
   })  : _position = position,
         _paths = paths,
-        _categoryBits = categoryBits ?? Filter().categoryBits {
+        _layer = layer {
     paint = Paint()
       ..color = color ?? const Color.fromARGB(0, 0, 0, 0)
       ..style = PaintingStyle.stroke;
@@ -38,7 +39,7 @@ class Pathway extends BodyComponent {
     required double width,
     double rotation = 0,
     bool singleWall = false,
-    int? categoryBits,
+    Layer? layer,
   }) {
     final paths = <List<Vector2>>[];
 
@@ -61,7 +62,7 @@ class Pathway extends BodyComponent {
       color: color,
       position: position,
       paths: paths,
-      categoryBits: categoryBits,
+      layer: layer,
     );
   }
 
@@ -87,7 +88,7 @@ class Pathway extends BodyComponent {
     required double angle,
     double rotation = 0,
     bool singleWall = false,
-    int? categoryBits,
+    Layer? layer,
   }) {
     final paths = <List<Vector2>>[];
 
@@ -114,7 +115,7 @@ class Pathway extends BodyComponent {
       color: color,
       position: position,
       paths: paths,
-      categoryBits: categoryBits,
+      layer: layer,
     );
   }
 
@@ -134,7 +135,7 @@ class Pathway extends BodyComponent {
     required double width,
     double rotation = 0,
     bool singleWall = false,
-    int? categoryBits,
+    Layer? layer,
   }) {
     final paths = <List<Vector2>>[];
 
@@ -157,13 +158,13 @@ class Pathway extends BodyComponent {
       color: color,
       position: position,
       paths: paths,
-      categoryBits: categoryBits,
+      layer: layer,
     );
   }
 
   Vector2 _position;
   List<List<Vector2>> _paths;
-  int _categoryBits;
+  Layer? _layer;
 
   @override
   Body createBody() {
@@ -179,7 +180,8 @@ class Pathway extends BodyComponent {
         );
       final fixtureDef = FixtureDef(chain);
 
-      body.createFixture(fixtureDef).filterData.categoryBits = _categoryBits;
+      body.createFixture(fixtureDef).filterData.categoryBits =
+          _layer?.maskBits ?? Filter().categoryBits;
     }
 
     return body;
diff --git a/lib/game/components/sparky_ramp.dart b/lib/game/components/sparky_ramp.dart
index bae9ca0c..54aaf33d 100644
--- a/lib/game/components/sparky_ramp.dart
+++ b/lib/game/components/sparky_ramp.dart
@@ -32,7 +32,7 @@ class SparkyRamp extends Component with HasGameRef<PinballGame> {
         radius: _radius,
         angle: _angle,
         width: _width,
-        categoryBits: RampType.sparky.maskBits,
+        layer: Layer.sparky,
       ),
     );
     await add(
@@ -54,9 +54,7 @@ class SparkyRamp extends Component with HasGameRef<PinballGame> {
 }
 
 /// {@template sparky_ramp_opening}
-/// Implementation of [RampOpening] for sensors in [SparkyRamp].
-///
-/// [RampOpening] with [RampType.sparky] to filter [Ball]s collisions
+/// [RampOpening] with [Layer.sparky] to filter [Ball]s collisions
 /// inside [SparkyRamp].
 /// {@endtemplate}
 class SparkyRampOpening extends RampOpening {
@@ -69,7 +67,7 @@ class SparkyRampOpening extends RampOpening {
         _orientation = orientation,
         super(
           position: position,
-          layer: RampType.sparky,
+          layer: Layer.sparky,
         );
 
   /// Orientation of entrance/exit of [SparkyRamp] where
@@ -97,8 +95,8 @@ class SparkyRampOpening extends RampOpening {
 }
 
 /// {@template sparky_ramp_opening_ball_contact_callback}
-/// Implementation of [RampOpeningBallContactCallback] to listen when a [Ball]
-/// gets into a [SparkyRampOpening].
+/// Detects when a [Ball] enters or exits the [SparkyRamp] through a
+/// [SparkyRampOpening].
 /// {@endtemplate}
 class SparkyRampOpeningBallContactCallback
     extends RampOpeningBallContactCallback<SparkyRampOpening> {
diff --git a/test/game/components/ball_test.dart b/test/game/components/ball_test.dart
index 8bdcc99b..de15c24c 100644
--- a/test/game/components/ball_test.dart
+++ b/test/game/components/ball_test.dart
@@ -172,7 +172,7 @@ void main() {
       flameTester.test(
         'modifies layer correctly',
         (game) async {
-          const newLayer = RampType.jetpack;
+          const newLayer = Layer.jetpack;
 
           final ball = Ball(position: Vector2.zero());
           await game.ensureAdd(ball);
@@ -182,7 +182,7 @@ void main() {
           expect(fixture.filterData.categoryBits, equals(1));
           expect(fixture.filterData.maskBits, equals(Filter().maskBits));
 
-          ball.setLayer(newLayer);
+          ball.layer = newLayer;
 
           expect(fixture.filterData.categoryBits, equals(newLayer.maskBits));
           expect(fixture.filterData.maskBits, equals(newLayer.maskBits));
diff --git a/test/game/components/jetpack_ramp_test.dart b/test/game/components/jetpack_ramp_test.dart
index 26779aaf..e0037156 100644
--- a/test/game/components/jetpack_ramp_test.dart
+++ b/test/game/components/jetpack_ramp_test.dart
@@ -80,7 +80,7 @@ void main() {
     });
   });
 
-  group('JetpackRampArea', () {
+  group('JetpackRampOpening', () {
     flameTester.test(
       'orientation is down',
       (game) async {
@@ -97,7 +97,7 @@ void main() {
     );
   });
 
-  group('JetpackRampAreaCallback', () {
+  group('JetpackRampOpeningBallContactCallback', () {
     test('has no ball inside on creation', () {
       expect(
         JetpackRampOpeningBallContactCallback().ballsInside,
diff --git a/test/game/components/crossing_ramp_test.dart b/test/game/components/layer_test.dart
similarity index 74%
rename from test/game/components/crossing_ramp_test.dart
rename to test/game/components/layer_test.dart
index b4f76579..f8df221d 100644
--- a/test/game/components/crossing_ramp_test.dart
+++ b/test/game/components/layer_test.dart
@@ -7,11 +7,11 @@ import 'package:pinball/game/game.dart';
 
 import '../../helpers/helpers.dart';
 
-class TestRampArea extends RampOpening {
-  TestRampArea({
+class TestRampOpening extends RampOpening {
+  TestRampOpening({
     required Vector2 position,
     required RampOrientation orientation,
-    required RampType layer,
+    required Layer layer,
   })  : _orientation = orientation,
         super(position: position, layer: layer);
 
@@ -30,9 +30,9 @@ class TestRampArea extends RampOpening {
     ]);
 }
 
-class TestRampAreaCallback
-    extends RampOpeningBallContactCallback<TestRampArea> {
-  TestRampAreaCallback() : super();
+class TestRampOpeningBallContactCallback
+    extends RampOpeningBallContactCallback<TestRampOpening> {
+  TestRampOpeningBallContactCallback() : super();
 
   final _ballsInside = <Ball>{};
 
@@ -41,37 +41,43 @@ class TestRampAreaCallback
 }
 
 void main() {
-  group('RampType', () {
+  group('Layer', () {
     test('has three values', () {
-      expect(RampType.values.length, equals(3));
+      expect(Layer.values.length, equals(3));
     });
   });
 
-  group('RampTypeX', () {
+  group('LayerX', () {
+    test('all types are different', () {
+      expect(Layer.all.maskBits, isNot(equals(Layer.jetpack.maskBits)));
+      expect(Layer.jetpack.maskBits, isNot(equals(Layer.sparky.maskBits)));
+      expect(Layer.sparky.maskBits, isNot(equals(Layer.all.maskBits)));
+    });
+
     test('all type has default maskBits', () {
-      expect(RampType.all.maskBits, equals(Filter().maskBits));
+      expect(Layer.all.maskBits, equals(0xFFFF));
     });
 
     test('jetpack type has 0x010 maskBits', () {
-      expect(RampType.jetpack.maskBits, equals(0x010));
+      expect(Layer.jetpack.maskBits, equals(0x0010));
     });
 
     test('sparky type has 0x0100 maskBits', () {
-      expect(RampType.sparky.maskBits, equals(0x0100));
+      expect(Layer.sparky.maskBits, equals(0x0100));
     });
   });
 
-  group('RampArea', () {
+  group('RampOpening', () {
     TestWidgetsFlutterBinding.ensureInitialized();
     final flameTester = FlameTester(PinballGameTest.create);
 
     flameTester.test(
       'loads correctly',
       (game) async {
-        final ramp = TestRampArea(
+        final ramp = TestRampOpening(
           position: Vector2.zero(),
           orientation: RampOrientation.down,
-          layer: RampType.all,
+          layer: Layer.all,
         );
         await game.ready();
         await game.ensureAdd(ramp);
@@ -85,10 +91,10 @@ void main() {
         'positions correctly',
         (game) async {
           final position = Vector2.all(10);
-          final ramp = TestRampArea(
+          final ramp = TestRampOpening(
             position: position,
             orientation: RampOrientation.down,
-            layer: RampType.all,
+            layer: Layer.all,
           );
           await game.ensureAdd(ramp);
 
@@ -100,10 +106,10 @@ void main() {
       flameTester.test(
         'is static',
         (game) async {
-          final ramp = TestRampArea(
+          final ramp = TestRampOpening(
             position: Vector2.zero(),
             orientation: RampOrientation.down,
-            layer: RampType.all,
+            layer: Layer.all,
           );
           await game.ensureAdd(ramp);
 
@@ -111,13 +117,13 @@ void main() {
         },
       );
 
-      group('fixtures', () {
-        const layer = RampType.jetpack;
+      group('fixture', () {
+        const layer = Layer.jetpack;
 
         flameTester.test(
           'exists',
           (game) async {
-            final ramp = TestRampArea(
+            final ramp = TestRampOpening(
               position: Vector2.zero(),
               orientation: RampOrientation.down,
               layer: layer,
@@ -131,7 +137,7 @@ void main() {
         flameTester.test(
           'shape is a polygon',
           (game) async {
-            final ramp = TestRampArea(
+            final ramp = TestRampOpening(
               position: Vector2.zero(),
               orientation: RampOrientation.down,
               layer: layer,
@@ -146,7 +152,7 @@ void main() {
         flameTester.test(
           'is sensor',
           (game) async {
-            final ramp = TestRampArea(
+            final ramp = TestRampOpening(
               position: Vector2.zero(),
               orientation: RampOrientation.down,
               layer: layer,
@@ -161,7 +167,7 @@ void main() {
         flameTester.test(
           'sets filter categoryBits correctly',
           (game) async {
-            final ramp = TestRampArea(
+            final ramp = TestRampOpening(
               position: Vector2.zero(),
               orientation: RampOrientation.down,
               layer: layer,
@@ -180,20 +186,20 @@ void main() {
     });
   });
 
-  group('RampAreaCallback', () {
-    const layer = RampType.jetpack;
+  group('RampOpeningBallContactCallback', () {
+    const layer = Layer.jetpack;
 
     test(
         'a ball enters from bottom into a down oriented path and keeps inside, '
         'is saved into collection and set maskBits to path', () {
       final ball = MockBall();
       final body = MockBody();
-      final area = TestRampArea(
+      final area = TestRampOpening(
         position: Vector2(0, 10),
         orientation: RampOrientation.down,
         layer: layer,
       );
-      final callback = TestRampAreaCallback();
+      final callback = TestRampOpeningBallContactCallback();
 
       when(() => body.position).thenReturn(Vector2(0, 20));
       when(() => ball.body).thenReturn(body);
@@ -203,11 +209,11 @@ void main() {
 
       expect(callback._ballsInside.length, equals(1));
       expect(callback._ballsInside.first, ball);
-      verify(() => ball.setLayer(layer)).called(1);
+      verify(() => ball.layer = layer).called(1);
 
       callback.end(ball, area, MockContact());
 
-      verifyNever(() => ball.setLayer(RampType.all));
+      verifyNever(() => ball.layer = Layer.all);
     });
 
     test(
@@ -215,12 +221,12 @@ void main() {
         'is saved into collection and set maskBits to path', () {
       final ball = MockBall();
       final body = MockBody();
-      final area = TestRampArea(
+      final area = TestRampOpening(
         position: Vector2(0, 10),
         orientation: RampOrientation.up,
         layer: layer,
       );
-      final callback = TestRampAreaCallback();
+      final callback = TestRampOpeningBallContactCallback();
 
       when(() => body.position).thenReturn(Vector2.zero());
       when(() => ball.body).thenReturn(body);
@@ -230,11 +236,11 @@ void main() {
 
       expect(callback._ballsInside.length, equals(1));
       expect(callback._ballsInside.first, ball);
-      verify(() => ball.setLayer(layer)).called(1);
+      verify(() => ball.layer = layer).called(1);
 
       callback.end(ball, area, MockContact());
 
-      verifyNever(() => ball.setLayer(RampType.all));
+      verifyNever(() => ball.layer = Layer.all);
     });
 
     test(
@@ -242,12 +248,12 @@ void main() {
         'is removed from collection and set maskBits to collide all', () {
       final ball = MockBall();
       final body = MockBody();
-      final area = TestRampArea(
+      final area = TestRampOpening(
         position: Vector2(0, 10),
         orientation: RampOrientation.down,
         layer: layer,
       );
-      final callback = TestRampAreaCallback();
+      final callback = TestRampOpeningBallContactCallback();
 
       when(() => body.position).thenReturn(Vector2.zero());
       when(() => ball.body).thenReturn(body);
@@ -257,11 +263,11 @@ void main() {
 
       expect(callback._ballsInside.length, equals(1));
       expect(callback._ballsInside.first, ball);
-      verify(() => ball.setLayer(layer)).called(1);
+      verify(() => ball.layer = layer).called(1);
 
       callback.end(ball, area, MockContact());
 
-      verify(() => ball.setLayer(RampType.all));
+      verify(() => ball.layer = Layer.all);
     });
 
     test(
@@ -269,12 +275,13 @@ void main() {
         'is removed from collection and set maskBits to collide all', () {
       final ball = MockBall();
       final body = MockBody();
-      final area = TestRampArea(
+      final area = TestRampOpening(
         position: Vector2(0, 10),
         orientation: RampOrientation.down,
         layer: layer,
       );
-      final callback = TestRampAreaCallback()..ballsInside.add(ball);
+      final callback = TestRampOpeningBallContactCallback()
+        ..ballsInside.add(ball);
 
       when(() => body.position).thenReturn(Vector2.zero());
       when(() => ball.body).thenReturn(body);
@@ -282,11 +289,11 @@ void main() {
       callback.begin(ball, area, MockContact());
 
       expect(callback._ballsInside.isEmpty, isTrue);
-      verify(() => ball.setLayer(RampType.all)).called(1);
+      verify(() => ball.layer = Layer.all).called(1);
 
       callback.end(ball, area, MockContact());
 
-      verify(() => ball.setLayer(RampType.all)).called(1);
+      verify(() => ball.layer = Layer.all).called(1);
     });
 
     test(
@@ -294,12 +301,13 @@ void main() {
         'is removed from collection and set maskBits to collide all', () {
       final ball = MockBall();
       final body = MockBody();
-      final area = TestRampArea(
+      final area = TestRampOpening(
         position: Vector2(0, 10),
         orientation: RampOrientation.up,
         layer: layer,
       );
-      final callback = TestRampAreaCallback()..ballsInside.add(ball);
+      final callback = TestRampOpeningBallContactCallback()
+        ..ballsInside.add(ball);
 
       when(() => body.position).thenReturn(Vector2(0, 20));
       when(() => ball.body).thenReturn(body);
@@ -307,11 +315,11 @@ void main() {
       callback.begin(ball, area, MockContact());
 
       expect(callback._ballsInside.isEmpty, isTrue);
-      verify(() => ball.setLayer(RampType.all)).called(1);
+      verify(() => ball.layer = Layer.all).called(1);
 
       callback.end(ball, area, MockContact());
 
-      verify(() => ball.setLayer(RampType.all)).called(1);
+      verify(() => ball.layer = Layer.all).called(1);
     });
   });
 }
diff --git a/test/game/components/pathway_test.dart b/test/game/components/pathway_test.dart
index f1142b71..443c1f96 100644
--- a/test/game/components/pathway_test.dart
+++ b/test/game/components/pathway_test.dart
@@ -176,13 +176,13 @@ void main() {
         flameTester.test(
           'sets filter categoryBits correctly',
           (game) async {
-            const maskBits = 1234;
+            const layer = Layer.jetpack;
             final pathway = Pathway.straight(
               position: Vector2.zero(),
               start: Vector2(10, 10),
               end: Vector2(20, 20),
               width: width,
-              categoryBits: maskBits,
+              layer: layer,
             );
             await game.ready();
             await game.ensureAdd(pathway);
@@ -191,7 +191,7 @@ void main() {
               expect(fixture, isA<Fixture>());
               expect(
                 fixture.filterData.categoryBits,
-                equals(maskBits),
+                equals(layer.maskBits),
               );
             }
           },
diff --git a/test/game/components/sparky_ramp_test.dart b/test/game/components/sparky_ramp_test.dart
index 366d150d..32ce0845 100644
--- a/test/game/components/sparky_ramp_test.dart
+++ b/test/game/components/sparky_ramp_test.dart
@@ -80,7 +80,7 @@ void main() {
     });
   });
 
-  group('SparkyRampArea', () {
+  group('SparkyRampOpening', () {
     flameTester.test(
       'orientation is down',
       (game) async {
@@ -97,7 +97,7 @@ void main() {
     );
   });
 
-  group('SparkyRampAreaCallback', () {
+  group('SparkyRampOpeningBallContactCallback', () {
     test('has no ball inside on creation', () {
       expect(
         SparkyRampOpeningBallContactCallback().ballsInside,