SpikeBall.cs

using UnityEngine;
using System.Collections;

public class SpikeBall : MonoBehaviour
{
    //a holder for our Animator
    Animator anim;
    //a public float for the explosion radius
    private Vector2 movement;
    private Rigidbody2D rigidbodyComponent;
    GameObject objToSpawn;
    // Use this for initialization
    public Collider2D[] colliders;
    public static int lives = 3;

    void Start()
    {
        anim = GetComponent<Animator>();
    }

    void FixedUpdate()
    {
        if (rigidbodyComponent == null) rigidbodyComponent = GetComponent<Rigidbody2D>();

        // Apply movement to the rigidbody
        rigidbodyComponent.velocity = movement;
    }

    void OnTriggerEnter2D(Collider2D other)
    {
        if (other.tag == "Player1")
        {
            //other.GetComponent<Renderer>().enabled = false;
            /*if (Global.count <= 0)
            {
                Destroy(other.gameObject);
            }
            else
            {
                Global.count = Global.count - 1;
                Global.DisplayHearts();
            }*/
            SpecialEffectsHelper.Instance.Explosion(transform.position); //EXPLOSION!!!
            Destroy(other.gameObject);
            
            //other.gameObject.SetActive(false);
        }

        else if (other.tag == "Player2")
        {
            //other.GetComponent<Renderer>().enabled = false;
            /*if (Global.count <= 0)
            {
                Destroy(other.gameObject);
            }
            else
            {
                Global.count = Global.count - 1;
                Global.DisplayHearts();
            }*/
            SpecialEffectsHelper.Instance.Explosion(transform.position); //EXPLOSION!!!
            Destroy(other.gameObject);
            
            /*if (lives <= 0)
            {
                Destroy(other.gameObject);
                lives = lives - 1;
            }*/
            //other.gameObject.SetActive(false);
        }
    }

}

This simple script, which is attached to a SpikeBall object, allows the object to destroy players upon collision. In my settings, I have increased the gravity scale so that it falls at a very high speed, adding greater difficulty to the game.