// Instantiates a project after 2 seconds when Space key was pressed
// and it will only call the function after the function has ended its execution

var projectile : Rigidbody;

function Update() { 
    if(Input.GetKeyDown(KeyCode.Space) && !IsInvoking("LaunchProjectile"))
        Invoke("LaunchProjectile", 2);
}

function LaunchProjectile () {
    var instance : Rigidbody = Instantiate(projectile);
    instance.velocity = Random.insideUnitSphere * 5;
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Rigidbody projectile;
    void Update() {
        if (Input.GetKeyDown(KeyCode.Space) && !IsInvoking("LaunchProjectile"))
            Invoke("LaunchProjectile", 2);
        
    }
    void LaunchProjectile() {
        Rigidbody instance = Instantiate(projectile);
        instance.velocity = Random.insideUnitSphere * 5;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public projectile as Rigidbody

    def Update():
        if Input.GetKeyDown(KeyCode.Space) and (not IsInvoking('LaunchProjectile')):
            Invoke('LaunchProjectile', 2)

    def LaunchProjectile():
        instance as Rigidbody = Instantiate(projectile)
        instance.velocity = (Random.insideUnitSphere * 5)