Unity Free Flight Camera

using UnityEngine;

public class FreeFlightCamera : MonoBehaviour
{
    public static readonly string[] Description = new string[]
    {
        "WASD to move",
        "RMB to rotate",
        "Space, Ctrl to jump",
        "Shift to accelerate"
    };

    public bool DrawInfo = true;
    public float LiniarSpeed = 10;
    public float AngularRotationArc = 130;

    private Vector3 _lastMousePosition;

    private void SimulateMotion(float deltaTime)
    {
        var motion = Vector3.zero;
        var jump = Vector3.zero;
        if (Input.GetKey(KeyCode.W)) motion.z = 1;
        if (Input.GetKey(KeyCode.S)) motion.z = -1;
        if (Input.GetKey(KeyCode.D)) motion.x = 1;
        if (Input.GetKey(KeyCode.A)) motion.x = -1;
        if (Input.GetKey(KeyCode.Space)) jump.y = 1;
        if (Input.GetKey(KeyCode.LeftControl)) jump.y = -1;
        motion = deltaTime * LiniarSpeed * motion.normalized;
        jump = deltaTime * LiniarSpeed * jump;
        if (Input.GetKey(KeyCode.LeftShift))
        {
            motion *= 5;
            jump *= 5;
        }
        transform.Translate(motion);
        transform.Translate(jump, Space.World);
    }

    private void SimulateRotation()
    {
        if (Input.GetMouseButtonDown(1))
            _lastMousePosition = Input.mousePosition;
        if (Input.GetMouseButton(1))
        {
            var mouseDelta = Input.mousePosition - _lastMousePosition;
            var x = Mathf.Abs(mouseDelta.x / Screen.width) * AngularRotationArc * Mathf.Sign(mouseDelta.x);
            var y = -Mathf.Abs(mouseDelta.y / Screen.height) * AngularRotationArc * Mathf.Sign(mouseDelta.y);
            transform.Rotate(Vector3.right, y);
            transform.Rotate(0, x, 0, Space.World);
            _lastMousePosition = Input.mousePosition;
        }
    }

    private void Update()
    {
        SimulateMotion(Time.deltaTime);
        SimulateRotation();
    }

    private void OnGUI()
    {
        if (DrawInfo) DrawTextLines(Description);
    }

    private void DrawTextLines(string[] lines)
    {
        var lineHeight = 24;
        var lineWidth = 256;
        for(var i = 0; i < lines.Length; i++)
            GUI.TextField(new Rect(0, lineHeight * i, lineWidth, lineHeight), lines[i]);
    }
}