diff --git a/.github/composites/build/action.yml b/.github/composites/build/action.yml
index 5714a37..c578c32 100644
--- a/.github/composites/build/action.yml
+++ b/.github/composites/build/action.yml
@@ -6,7 +6,7 @@ runs:
     steps:
       - uses: krdlab/setup-haxe@v1
         with:
-          haxe-version: 4.2.4
+          haxe-version: 4.3.2
           
       - uses: actions/checkout@v3
         with:
@@ -16,7 +16,7 @@ runs:
         shell: bash
         run: |
           haxelib git dox https://github.com/HaxeFoundation/dox.git
-          haxelib git heaps https://github.com/HeapsIO/heaps.git
+          haxelib install heaps 2.0.0
           haxelib dev echo .
           
       - name: Run Builds
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 782aca5..2d19c9c 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,5 +1,6 @@
 {
     "[haxe]": {
-        "editor.formatOnSave": true
+        "editor.formatOnSave": true,
+        "files.trimTrailingWhitespace": false,
     }
-}
\ No newline at end of file
+}
diff --git a/assets/index.html b/assets/index.html
index 920ac76..2c33100 100644
--- a/assets/index.html
+++ b/assets/index.html
@@ -84,6 +84,8 @@
         <h1>Echo</h1>
         <p>Simple Arcade Physics Library for Haxe</p>
         <canvas width="640" height="360" id="webgl"></canvas>
+        <p style="font-style: italic; font-size: x-small; margin-bottom: 0.1em">Known issue: the sample buttons do not work correctly! as a quick fix, resize your browser window and they'll work just fine ;)</a></p>
+
         <div class="buttons">
             <a href="https://github.com/AustinEast/echo/">Get Started</a>
             <a href="./api/echo/Echo" target="_blank">API</a>
diff --git a/echo/Body.hx b/echo/Body.hx
index c1ce6ca..e13821e 100644
--- a/echo/Body.hx
+++ b/echo/Body.hx
@@ -198,11 +198,11 @@ class Body implements Disposable #if cog implements cog.IComponent #end {
   /**
    * If set, this method is called whenever the Body's X or Y changes.
    */
-  public var on_move:Null<Float->Float->Void>;
+  public var on_move:Null<(x:Float, y:Float) -> Void>;
   /**
    * If set, this method is called whenever the Body's rotation changes.
    */
-  public var on_rotate:Null<Float->Void>;
+  public var on_rotate:Null<(angle:Float) -> Void>;
 
   @:allow(echo.Physics.step_body)
   public var last_x(default, null):Float;
@@ -231,6 +231,7 @@ class Body implements Disposable #if cog implements cog.IComponent #end {
    * Sets a Body's values from a `BodyOptions` object.
    * @param options
    */
+  @:haxe.warning("-WDeprecated")
   public function load_options(?options:BodyOptions) {
     options = echo.util.JSON.copy_fields(options, defaults);
     clear_shapes();
diff --git a/echo/Echo.hx b/echo/Echo.hx
index 092e8a6..e3cc466 100644
--- a/echo/Echo.hx
+++ b/echo/Echo.hx
@@ -76,31 +76,46 @@ class Echo {
   /**
    * Steps a `World` forward.
    * @param world
-   * @param dt
+   * @param dt The Delta Time to step the `World` Forward
+   * @param rate The target rate of Step-Per-Second. If set to 0, the target rate is unlimited.
    */
-  public static function step(world:World, dt:Float) {
-    // Save World State to History
-    if (world.history != null) world.history.add([
-      for (b in world.members) {
-        id: b.id,
-        x: b.x,
-        y: b.y,
-        rotation: b.rotation,
-        velocity_x: b.velocity.x,
-        velocity_y: b.velocity.y,
-        acceleration_x: b.acceleration.x,
-        acceleration_y: b.acceleration.y,
-        rotational_velocity: b.rotational_velocity
+  public static function step(world:World, dt:Float, rate:Float = 0) {
+    function step_world(world:World, dt:Float) {
+      // Save World State to History
+      if (world.history != null) world.history.add([
+        for (b in world.members) {
+          id: b.id,
+          x: b.x,
+          y: b.y,
+          rotation: b.rotation,
+          velocity_x: b.velocity.x,
+          velocity_y: b.velocity.y,
+          acceleration_x: b.acceleration.x,
+          acceleration_y: b.acceleration.y,
+          rotational_velocity: b.rotational_velocity
+        }
+      ]);
+
+      // Step the World incrementally based on the number of iterations
+      var fdt = dt / world.iterations;
+      for (i in 0...world.iterations) {
+        Physics.step(world, fdt);
+        Collisions.query(world);
+        Physics.separate(world);
+        Collisions.notify(world);
       }
-    ]);
+    }
 
-    // Step the World incrementally based on the number of iterations
-    var fdt = dt / world.iterations;
-    for (i in 0...world.iterations) {
-      Physics.step(world, fdt);
-      Collisions.query(world);
-      Physics.separate(world);
-      Collisions.notify(world);
+    if (rate > 0) {
+      world.accumulatedTime += dt;
+      var step = 1.0 / rate;
+      while (world.accumulatedTime >= step) {
+        world.accumulatedTime -= step;
+        step_world(world, step);
+      }
+    }
+    else {
+      step_world(world, dt);
     }
   }
   /**
diff --git a/echo/Physics.hx b/echo/Physics.hx
index 2276cf8..9a9299f 100644
--- a/echo/Physics.hx
+++ b/echo/Physics.hx
@@ -52,7 +52,7 @@ class Physics {
 
       // Apply Rotational Acceleration, Drag, and Max Velocity
       var accel_rot = body.torque * body.inverse_mass;
-      body.rotational_velocity = compute_velocity(body.rotational_velocity, body.rotational_drag, accel_rot, body.max_rotational_velocity, dt);
+      body.rotational_velocity = compute_velocity(body.rotational_velocity, accel_rot, body.rotational_drag, body.max_rotational_velocity, dt);
 
       // Apply Rotational Velocity
       body.rotation += body.rotational_velocity * dt;
diff --git a/echo/World.hx b/echo/World.hx
index 8b010c2..b2072b6 100644
--- a/echo/World.hx
+++ b/echo/World.hx
@@ -52,6 +52,8 @@ class World implements Disposable {
 
   public var history:Null<History<Array<BodyState>>>;
 
+  public var accumulatedTime:Float = 0;
+
   var init:Bool;
 
   public function new(options:WorldOptions) {
diff --git a/echo/data/Data.hx b/echo/data/Data.hx
index 02eae63..7700094 100644
--- a/echo/data/Data.hx
+++ b/echo/data/Data.hx
@@ -244,7 +244,6 @@ class QuadTreeData {
   public var flag = false;
 }
 
-@:enum
-abstract Direction(Int) from Int to Int {
+enum abstract Direction(Int) from Int to Int {
   var TOP = 0;
 }
diff --git a/echo/data/Types.hx b/echo/data/Types.hx
index 0f25d2c..8315c05 100644
--- a/echo/data/Types.hx
+++ b/echo/data/Types.hx
@@ -1,17 +1,17 @@
 package echo.data;
 
-@:enum abstract MassType(Float) from Float to Float {
+enum abstract MassType(Float) from Float to Float {
   var AUTO = -1;
   var STATIC = 0;
 }
 
-@:enum abstract ShapeType(Int) from Int to Int {
+enum abstract ShapeType(Int) from Int to Int {
   var RECT;
   var CIRCLE;
   var POLYGON;
 }
 
-@:enum abstract ForceType(Int) from Int to Int {
+enum abstract ForceType(Int) from Int to Int {
   var ACCELERATION;
   var VELOCITY;
   var POSITION;
diff --git a/echo/util/Bezier.hx b/echo/util/Bezier.hx
index 09a7e07..6819d1d 100644
--- a/echo/util/Bezier.hx
+++ b/echo/util/Bezier.hx
@@ -600,7 +600,7 @@ class Bezier implements Disposable {
   }
 }
 
-@:enum abstract BezierCurve(Int) to Int from Int {
+enum abstract BezierCurve(Int) to Int from Int {
   var Linear = 1;
   var Quadratic = 2;
   var Cubic = 3;
diff --git a/haxelib.json b/haxelib.json
index 9f897b5..4a9e2fa 100644
--- a/haxelib.json
+++ b/haxelib.json
@@ -10,6 +10,6 @@
     "austineast"
   ],
   "url": "https://austineast.dev/echo",
-  "releasenote": "fix webpage gen",
-  "version": "4.2.2"
+  "releasenote": "revert regression",
+  "version": "4.2.4"
 }
diff --git a/sample/Main.hx b/sample/Main.hx
index 85c55e8..7e20393 100644
--- a/sample/Main.hx
+++ b/sample/Main.hx
@@ -1,7 +1,6 @@
 package;
 
-import state.test.ListenerState;
-import state.test.OverlappingSpawnState;
+import hxd.Window;
 import hxd.Key;
 import echo.Echo;
 import echo.World;
@@ -89,8 +88,8 @@ class Main extends BaseApp {
     var fdt = Key.isDown(Key.SHIFT) ? dt * 0.3 : dt;
     // Update the current Sample State
     fsm.step(fdt);
-    // Step the World Forward
-    if (playing) world.step(fdt);
+    // Step the World Forward, with a fixed step rate of 60 per second
+    if (playing) world.step(fdt, 60);
 
     // Update GUI text
     members_text.text = 'Bodies: ${world.count}';