Enemy2.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Enemy2 : MonoBehaviour
{
    //Basically the same script as the other enemies

        //Health
    public float maxHealth = 75; //health
    public float currentHealth;

    //Health bar UI
    public GameObject healthBarUI;
    public Slider slider;
    public GameObject enemie;
    public Transform ghost;

    //not used
    public int Shurikendamage = 10;

    public GameObject score; //shuriken

    //references
    public GameObject bullet;
    public Transform shotSpawn;
    public float fireRate;
    private float nextFire;



    void Start()
    {
        //ghost position there so it can drop score there 
        currentHealth = maxHealth;
        slider.value = CalculateHealth();
        ghost.position = new Vector3(ghost.position.x, ghost.position.y, ghost.position.z);

        fireRate = 3f;
        nextFire = Time.time;
    }

    void Update()
    {
        //failed attempt at healthbar being inactive on start
        slider.value = CalculateHealth();

        if (currentHealth < maxHealth)
        {
            healthBarUI.SetActive(true);
        }

        CheckIfTimeToFire();


    }

    //can he fire

    void CheckIfTimeToFire()
    {
        if (Time.time > nextFire)
        {
            Instantiate(bullet, shotSpawn.position, shotSpawn.rotation);
            nextFire = Time.time + fireRate;
        }
    }

    //take damage function
    public void TakeDamage(int damage)
    {
        healthBarUI.SetActive(true);

        currentHealth -= damage;
        slider.value = CalculateHealth();

        //Hurt Animation
        SoundManagerScript.PlaySound("GhostHurt");
        if (currentHealth <= 0)
        {
            Instantiate(score, new Vector3(ghost.position.x, ghost.position.y, ghost.position.z), Quaternion.identity);

            Die();
        }
    }

    void Die()
    {
        Destroy(enemie);
    }

    //collide with bullet

    private void OnTriggerEnter2D(Collider2D other)
    {
        if (other.gameObject.CompareTag("Bullet"))
        {
            other.gameObject.SetActive(false);
            TakeDamage(Shurikendamage);
            healthBarUI.SetActive(true);
            slider.value = CalculateHealth();
            SoundManagerScript.PlaySound("GhostHurt");
        }

    }

    float CalculateHealth()
    {
        return currentHealth / maxHealth;
    }
}