Ошибка System.NullReferenceException: "Ссылка на объект не указывает на экземпляр объекта."

Написал простенькую игру на C#, но при выполнении возникает эта ошибка, пожалуйста помогите решить. Ошибка возникает в самом конце кода ( enemies[i].Left)

    //----------------------------Main Abrs---------------------
//int BLs = Bullets speed
//int BGs = BackGround Speed
//int PRs = Player Speed
//timer Lmot = Left Motion Timer
//timer Rmot = Right Motion Timer
//timer Umot = Up Motion Timer
//timer Dmot = Down Motion Timer
//PRb = Player Box


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using WMPLib;

namespace WindowsFormsApp1
{
    public partial class Fprm1 : Form
    {

//Params
int PRs = 3;
int BGs = 2;
int BLs = 80;
        int ENs = 3;

        //adds
        PictureBox[] bullets;
PictureBox[] enemies;
PictureBox[] cloud;
Random rnd;
WindowsMediaPlayer GameSong;
WindowsMediaPlayer Shoot;

public Fprm1()
        {
            InitializeComponent();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            for (int i = 0; i < cloud.Length; i++)
            {
                cloud[i].Left += BGs;
                if (cloud[i].Left >= 1280)
                {
                    cloud[i].Left = cloud[i].Height;
                }
            }

            for (int i = cloud.Length; i < cloud.Length; i++)
            {
                cloud[i].Left += BGs - 10;

                if (cloud[i].Left >= 1280)
                {
                    cloud[i].Left = cloud[i].Left;
                }
            }
        }
//Base Form1
        private void Form1_Load(object sender, EventArgs e)
        {//Bullets alg
       


            bullets = new PictureBox[1];
            for (int i = 0; i < bullets.Length; i++)
            {
                bullets[i] = new PictureBox();
                bullets[i].BorderStyle = BorderStyle.None;
                bullets[i].Size = new Size(20, 5);
                bullets[i].BackColor = Color.White;
                this.Controls.Add(bullets[i]);
            }
         //clouds alg
            cloud = new PictureBox[20];
            rnd = new Random();
         

            for (int i = 0; i < cloud.Length; i++)
            {
                cloud[i] = new PictureBox();
                cloud[i].BorderStyle = BorderStyle.None;
                cloud[i].Location = new Point(rnd.Next(-1000, 1800), rnd.Next(50, 280));
                if (i % 2 == 1)
                {
                    cloud[i].Size = new Size(rnd.Next(100, 255), rnd.Next(30, 70));
                    cloud[i].BackColor = Color.FromArgb(rnd.Next(50, 120), 255, 160, 150);
                }
                else
                {
                    cloud[i].Size = new Size(150, 25);
                    cloud[i].BackColor = Color.FromArgb(rnd.Next(50, 125), 255, 205, 205);
                }
                this.Controls.Add(cloud[i]);
               
            }
         //Sounds alg
            Shoot = new WindowsMediaPlayer();
            Shoot.URL = "sounds\\shoot.mp3";
            Shoot.settings.volume = 100;

            GameSong = new WindowsMediaPlayer();
            GameSong.URL = "sounds\\GameSong.mp3";
            GameSong.settings.setMode("loop", true);
            GameSong.settings.volume = 5 ;
            GameSong.controls.play();
        }
//Moving Person
        private void Lmo_Tick(object sender, EventArgs e)
        {if (PRb.Left > 10){PRb.Left -= PRs;}}
        private void Rmot_Tick(object sender, EventArgs e)
        {if (PRb.Right > 10){PRb.Left += PRs;}}
        private void Umot_Tick(object sender, EventArgs e)
        {if (PRb.Top > 300) { PRb.Top -= PRs; }}
        private void Dmot_Tick(object sender, EventArgs e)
        {if (PRb.Top <600){PRb.Top += PRs;}}
//Keys 
        private void Fprm1_KeyDown(object sender, KeyEventArgs e)
        {PRb.Image = Properties.Resources.TankGO;
             if(e.KeyCode == Keys.Left){Lmot.Start();}
             if(e.KeyCode == Keys.Right){Rmot.Start();}
             if(e.KeyCode == Keys.Up){Umot.Start();}
             if(e.KeyCode == Keys.Down){Dmot.Start();}
             if(e.KeyCode == Keys.Space){
             for (int i = 0; i < bullets.Length; i++){if (bullets[i].Left > 1280){bullets[i].Location = new Point(PRb.Location.X + 100 + i * 50, PRb.Location.Y + 50);}}
             Shoot.controls.play();}

            //Enemies



        
            for (int i = 0; i < enemies.Length; i++)
            {
                 Image EzEN = Image.FromFile("assets\\EzEnemies.png");
                enemies = new PictureBox[4];
                int ENsz = rnd.Next(50, 100);
                enemies[i] = new PictureBox();
                enemies[i].Size = new Size(ENsz, ENsz);
                enemies[i].SizeMode = PictureBoxSizeMode.Zoom;
                enemies[i].BackColor = Color.Transparent;
                enemies[i].Image = EzEN;
                enemies[i].Location = new Point((i + 1) * rnd.Next(90, 160) + 1080, rnd.Next(450, 600));
                this.Controls.Add(enemies[i]);




            }
            
        }

        private void Fprm1_KeyUp(object sender, KeyEventArgs e)
        {
            PRb.Image = Properties.Resources.TankST;
            Lmot.Stop();
            Rmot.Stop();
            Umot.Stop();
            Dmot.Stop();
        }

 
        private void Bmot_Tick(object sender, EventArgs e)
        {
            for (int i = 0; i < bullets.Length; i++)
            {
                bullets[i].Left += BLs;

            }
        }

        private void Emot_Tick(object sender, EventArgs e)
        {

            MvEN(enemies, ENs);
        }

        private void MvEN(PictureBox[] enemies, int speed)
        {
           
            enemies = new PictureBox[4];

            for (int i = 1; i < enemies.Length; i++)
            {



                enemies = new PictureBox[4];
                enemies[i].Left -= ENs + (int)(Math.Sin(enemies[i].Left * Math.PI / 180) + Math.Cos(enemies[i].Left * Math.PI / 180));
            }
        }
    }
}