bug in unity 5?

i follow this tutorial for making flapping bird, but my bird “no go up” when i touch the screen


this is my script

using UnityEngine;
using System.Collections;

public class SpermMovement : MonoBehaviour
{
    Vector3 velocity = Vector3.zero;
    public Vector3 gravity;
    public Vector3 flapvelocity;

    bool didFlap = false;
    // Use this for initialization
    void Start(){

    }
    //DO GRAPHIC & INPUT UPDATE HERE
    void update() {
        if (Input.GetKeyDown(KeyCode.Space) || Input.GetMouseButtonDown(0) ) {
            didFlap = true;
        }

    }

    // DO PHYSICS ENGINE UPDATE HERE
    void FixedUpdate() { 
        velocity += gravity * Time.deltaTime;
        if (didFlap == true) { 
            didFlap = false;
            velocity += flapvelocity;
        }
        transform.position += velocity * Time.deltaTime;


    }
}

please help

The “bug in Unity 5” is that your update function is never called because you named it update and not Update.

Case sensitivty matters.

(And no, it’s not a bug in Unity, it’s a bug in your code)