Самый примитивный FPS контроллер

[RequireComponent(typeof(CharacterController))]
[RequireComponent(typeof(Camera))]
public class Player : MonoBehaviour
{
    public float MoveSpeed;

    CharacterController _controller;
    Camera _camera;
    GUIStyle _guiStyle;

    void Start()
    {
        _controller = GetComponent<CharacterController>();
        _camera = GetComponent<Camera>();
        _guiStyle = new GUIStyle()
        {
            fontSize = 8,
        };

        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
    }

    void Update()
    {
        float deltaX = Input.GetAxis("Horizontal") * MoveSpeed * Time.deltaTime;
        float deltaZ = Input.GetAxis("Vertical") * MoveSpeed * Time.deltaTime;

        _controller.transform.Translate(deltaX, 0, deltaZ);

        transform.Rotate(0, Input.GetAxis("Mouse X") * 9f, 0);
    }

    void OnGUI()
    {
        float x = _camera.pixelWidth / 2 - 4;
        float y = _camera.pixelHeight / 2 - 4;
        GUI.Label(new Rect(x, y, 1, 1), "+", _guiStyle);
    }
}

[RequireComponent(typeof(CharacterController))]
[RequireComponent(typeof(Camera))]