Simple SpriteKit demo in F#

// Updated version of source from https://neildanson.wordpress.com/2013/09/19/simple-spritekit-demo-in-f/

namespace Demo

open System
open System.Drawing

open Foundation
open UIKit
open SpriteKit
open CoreGraphics

[<Register ("ViewController")>]
type ViewController (handle:IntPtr) =
    inherit UIViewController (handle)

    override x.DidReceiveMemoryWarning () =
        // Releases the view if it doesn't have a superview.
        base.DidReceiveMemoryWarning ()
        // Release any cached data, images, etc that aren't in use.

    override x.ViewDidLoad () =
         base.ViewDidLoad ()
         //Create and configure the view
         let skView = new SKView()
         let width = x.View.Bounds.Width * UIScreen.MainScreen.Scale
         let height = x.View.Bounds.Height * UIScreen.MainScreen.Scale
         skView.Bounds <- CGRect(nfloat 0.0, nfloat 0.0, width, height)
         skView.ShowsFPS <- true
         skView.ShowsNodeCount <- true
         x.View <- skView

         //Create and configure the screen
         let scene =  new SKScene(skView.Bounds.Size)
         scene.BackgroundColor <- UIColor.Cyan
         scene.ScaleMode <- SKSceneScaleMode.AspectFill

         //Create a sprite
         let spriteNode = new SKSpriteNode "Spaceship"
         spriteNode.Position <- CGPoint(200.0,200.0)

         //Set a repeating 360 degree rotation
         let action = SKAction.RotateByAngle(nfloat Math.PI,1.0)
         let action = SKAction.RepeatActionForever action
         spriteNode.RunAction action

         //Add sprite to scene
         scene.AddChild spriteNode

         //Show scene
         skView.PresentScene scene

    override x.ShouldAutorotateToInterfaceOrientation (toInterfaceOrientation) =
        // Return true for supported orientations
        if UIDevice.CurrentDevice.UserInterfaceIdiom = UIUserInterfaceIdiom.Phone then
           toInterfaceOrientation <> UIInterfaceOrientation.PortraitUpsideDown
        else
           true