Re-definition/Assets/Resources/Entities/Bullet.cs

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

public class Bullet : MonoBehaviour {

    private void OnCollisionEnter2D(Collision2D collision) {
        AudioM.Play("bullet_explode");
        transform.localScale = Vector3.zero; Destroy(gameObject, 1);
    }

}