Tilemap.createCollisionObjects will parse Tiled data for objectgroups and convert polyline instances into physics objects you can collide with in the world.

After defining tiles that collide on a Tilemap, you need to call Tilemap.generateCollisionData(layer) to populate the physics world with the data required.
Debug.renderPhysicsBody updated to take camera location and body rotation into account.
Body movement functions put back to velocity :)
Updated to latest dev version of pixi and latest p2.js
Updated docs

src/physics/Body.js

@@ -222,6 +222,23 @@ Phaser.Physics.Body.prototype = {
 
     },
 
+    /**
+    * Applies a force to the Body that causes it to 'thrust' backwards (in reverse), based on its current angle and the given speed.
+    * The speed is represented in pixels per second. So a value of 100 would move 100 pixels in 1 second (1000ms).
+    *
+    * @method Phaser.Physics.Body#rever
+    * @param {number} speed - The speed at which it should reverse.
+    */
+    reverse: function (speed) {
+
+        var magnitude = this.px2p(-speed);
+        var angle = this.data.angle + Math.PI / 2;
+
+        this.data.force[0] -= magnitude * Math.cos(angle);
+        this.data.force[1] -= magnitude * Math.sin(angle);
+
+    },
+
     /**
     * If this Body is dynamic then this will move it to the left by setting its x velocity to the given speed.
     * The speed is represented in pixels per second. So a value of 100 would move 100 pixels in 1 second (1000ms).
@@ -231,8 +248,7 @@ Phaser.Physics.Body.prototype = {
     */
     moveLeft: function (speed) {
 
-        // this.data.velocity[0] = this.px2p(-speed);
-        this.data.force[0] += this.px2p(-speed);
+        this.data.velocity[0] = this.px2p(-speed);
 
     },
 
@@ -245,8 +261,7 @@ Phaser.Physics.Body.prototype = {
     */
     moveRight: function (speed) {
 
-        // this.data.velocity[0] = this.px2p(speed);
-        this.data.force[0] += this.px2p(speed);
+        this.data.velocity[0] = this.px2p(speed);
 
     },
 
@@ -259,8 +274,7 @@ Phaser.Physics.Body.prototype = {
     */
     moveUp: function (speed) {
 
-        // this.data.velocity[1] = this.px2p(-speed);
-        this.data.force[1] += this.px2p(-speed);
+        this.data.velocity[1] = this.px2p(-speed);
 
     },
 
@@ -273,8 +287,7 @@ Phaser.Physics.Body.prototype = {
     */
     moveDown: function (speed) {
 
-        // this.data.velocity[1] = this.px2p(speed);
-        this.data.force[1] += this.px2p(speed);
+        this.data.velocity[1] = this.px2p(speed);
 
     },
 
@@ -551,14 +564,19 @@ Phaser.Physics.Body.prototype = {
         //  Did they pass in a single array of points?
         if (points.length === 1 && Array.isArray(points[0]))
         {
-            path = path.concat(points[0]);
+            path = points[0].slice(0);
         }
         else if (Array.isArray(points[0]))
         {
-            path = path.concat(points);
+            path = points[0].slice(0);
+            // for (var i = 0, len = points[0].length; i < len; i += 2)
+            // {
+            //     path.push([points[0][i], points[0][i + 1]]);
+            // }
         }
         else if (typeof points[0] === 'number')
         {
+            // console.log('addPolygon --- We\'ve a list of numbers');
             //  We've a list of numbers
             for (var i = 0, len = points.length; i < len; i += 2)
             {
@@ -566,6 +584,18 @@ Phaser.Physics.Body.prototype = {
             }
         }
 
+        // console.log('addPolygon PATH pre');
+        // console.log(path[1]);
+        // console.table(path);
+
+        //  top and tail
+        var idx = path.length - 1;
+
+        if ( path[idx][0] === path[0][0] && path[idx][1] === path[0][1] )
+        {
+            path.pop();
+        }
+
         //  Now process them into p2 values
         for (var p = 0; p < path.length; p++)
         {
@@ -573,6 +603,10 @@ Phaser.Physics.Body.prototype = {
             path[p][1] = this.px2p(path[p][1]);
         }
 
+        // console.log('addPolygon PATH POST');
+        // console.log(path[1]);
+        // console.table(path);
+
         return this.data.fromPolygon(path, options);
 
     },

src/physics/World.js

@@ -255,7 +255,12 @@ Phaser.Physics.World.prototype.createBody = function (x, y, mass, addToWorld, op
 
     if (data)
     {
-        body.addPolygon(options, data);
+        var result = body.addPolygon(options, data);
+
+        if (!result)
+        {
+            return false;
+        }
     }
 
     if (addToWorld)