Unity sample project, roll-a-ball F# version

CameraController.fs

namespace RollABall

open UnityEngine

type CameraController() =
    inherit UnityEngine.MonoBehaviour()
     
    [<DefaultValue>] val mutable player : GameObject
    
    let mutable offset : Vector3 = Unchecked.defaultof<Vector3>

    member this.Start() =
        offset <- this.transform.position - this.player.transform.position
        
    member this.LateUpdate() =
        this.transform.position <- this.player.transform.position + offset

PlayerController.fs

namespace RollABall

open UnityEngine
open UnityEngine.UI

type PlayerController() =
    inherit UnityEngine.MonoBehaviour()
     
    [<DefaultValue>] val mutable speed : float32
    [<DefaultValue>] val mutable conutText : Text
    [<DefaultValue>] val mutable winText : Text
    
    let mutable rb : Rigidbody = Unchecked.defaultof<Rigidbody>
    let mutable count : int = 0
    
    member this.Start() =
        rb <- this.GetComponent<Rigidbody>()
        
        count <- 0
        
        this.SetCountText()
        
        this.winText.text <- ""
        
    member this.FixedUpdate() =
        let moveHorizontal = Input.GetAxis ("Horizontal")
        let moveVertical = Input.GetAxis ("Vertical")
        
        let movement = new Vector3 (moveHorizontal, 0.0f, moveVertical)
        
        (movement * this.speed) |> rb.AddForce
        
    member this.OnTriggerEnter(other : Collider) =
        if other.gameObject.CompareTag("Pick Up") then
            false |> other.gameObject.SetActive
            
            count <- count + 1
            
            this.SetCountText()
            
    member this.SetCountText() =
        let countDesc = sprintf "Count: %i" count
        this.conutText.text <- countDesc
        
        if count >= 12 then
            this.winText.text <- "You win"

Rotator.fs

namespace RollABall

open UnityEngine

type Rotator() =
    inherit UnityEngine.MonoBehaviour()
     
    member this.Update() =
        (new Vector3(15.0f, 30.0f, 45.0f) * Time.deltaTime) |> this.transform.Rotate