Q: How to make 2d game with many RIGIDBODIES run smooth?

In my game I would like to have around 100 rigidbodies. Every one of them has a scrip, an explosion effect and a collider .It is a homing missile game. What can I do to make it run smoother? After about 50 missiles it starts to run slower. Can I disable the rigidbodies until I use them? I have attached the homing missile script.

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



[RequireComponent(typeof(Rigidbody2D))]
public class HomingMissile : MonoBehaviour {



	


	public Transform target;

	public float delay ;

	public float speed = 5f;
	public float rotateSpeed = 200f;
	public GameObject ExplosionEffect;

	private Rigidbody2D rb;




	
	IEnumerator Start () {


		yield return new WaitForSeconds(delay);
		rb = GetComponent<Rigidbody2D>();

	}





	void FixedUpdate () {

		
		Vector2 direction = (Vector2)target.position - rb.position;

		direction.Normalize();

		float rotateAmount = Vector3.Cross(direction, transform.up).z;

		rb.angularVelocity = -rotateAmount * rotateSpeed;

		rb.velocity = transform.up * speed;

	                     }




	                   
	void OnTriggerEnter2D ()
	{
		
		Destroy(gameObject);
	     Instantiate(ExplosionEffect, transform.position, transform.rotation);
		
		ScoreScript.scoreValue += 1;


	}






}

Maybe consider just having the objs the bombs are colliding with have the RB’s instead of all those missles and just have colliders in them. Also maybe disable the rbs of non projectiles when they are not in cam view.

Well there is a video by brackeys where he adds a hell ton of rigidbodies and maze navigators. In there you can find the methods he used to make unity run smoother (mostly changing graphic settings).