Body.setVelocity was cause the speed property to be set to NaN if you didn't provide a y argument.

Author: photonstorm

CHANGELOG.md

@@ -35,6 +35,7 @@ Notes:
 * The `Body.delta` values are now able to be read and acted upon during a Scene update, due to the new game step flow. This means you can now call `this.physics.collide` during a Scene `update` and it will work properly again. Fix #4370 (thanks @NokFrt)
 * `ArcadePhysics.furthest` now iterates the bodies Set, rather than the RTree, which keeps it working even if the RTree has been disabled.
 * `ArcadePhysics.closest` now iterates the bodies Set, rather than the RTree, which keeps it working even if the RTree has been disabled.
+* `Body.setVelocity` was cause the `speed` property to be set to `NaN` if you didn't provide a `y` argument.
 
 ### Facebook Instant Games Plugin
 

src/physics/arcade/Body.js

@@ -1054,11 +1054,6 @@ var Body = new Class({
         {
             this.world.updateMotion(this, delta);
 
-            // if (!this.sleeping && this.gameObject.name === 'vu1')
-            // {
-            //     console.log(this.world._frame, 'UP Y', velocity.y, position.y, this.prev.y, this.blockers.length);
-            // }
-
             if (this.collideWorldBounds && !this.worldBlocked.none)
             {
                 this.checkWorldRebound();
@@ -1273,7 +1268,7 @@ var Body = new Class({
             this.sleeping = true;
 
             console.log(this.gameObject.name, 'put to sleep on frame', this.world._frame, 'force?', forceY, 'at', this.y);
-
+    
             this.velocity.set(0);
             this.prevVelocity.set(0);
             this.speed = 0;
@@ -2084,6 +2079,9 @@ var Body = new Class({
     {
         this.velocity.set(x, y);
 
+        x = this.velocity.x;
+        y = this.velocity.y;
+
         this.speed = Math.sqrt(x * x + y * y);
 
         return this;