public void Update()
        {
            if (IsUpButtonPressed)
            {
                if (player.Speed < 0)
                {
                    player.Speed = 0;
                }
                if (player.Speed < player.MAX_SPEED)
                {
                    player.Speed++;
                }
            }
            else
            {
                if (player.Speed > 0)
                {
                    player.Speed--;
                }
            }
            if (IsDownButtonPressed)
            {
                if (player.Speed > 0)
                {
                    player.Speed = 0;
                }
                if (player.Speed > -player.MAX_SPEED)
                {
                    player.Speed--;
                }
            }
            else
            {
                if (player.Speed < 0)
                {
                    player.Speed++;
                }
            }
            if (IsLeftButtonPressed)
            {
                player.Rotate(player.ROTATE_DEGREE_INCREMENT);
            }
            if (IsRightButtonPressed)
            {
                player.Rotate(-player.ROTATE_DEGREE_INCREMENT);
            }
            if (IsSpaceBarPressed)
            {
                App.soundPlayer.Play();
                if (player.LastFired == player.FIRE_COOLDOWN && !player.IsDead())
                {
                    player.LastFired = 0;
                    Bullet newBullet = new Bullet(VMath.AddVectors(player.Position, new Vector2(rand.Next(8) - 4, rand.Next(8) - 4)), player.UnitDirectionVector, 20, 3);
                    gameObjects.Add(newBullet);
                }
            }
            if (rand.Next(1, 100) <= 1) //random asteroid spawn chance
            {
                Asteroid newAsteroid = new Asteroid(new Vector2(rand.Next(0, canvasWidth), 0), new Vector2(rand.Next(-180, 180), rand.Next(-180, 180)), rand.Next(1, 5), rand.Next(15, 100));
                gameObjects.Add(newAsteroid);
            }

            foreach (var obj in gameObjects.Where((h => (h is HealthBar))).ToList())
            {
                gameObjects.Remove(obj);
            }
            HealthBar gameHealthBar = new HealthBar(new Vector2(canvasWidth, canvasHeight), new Vector2(0, 0), 0, player.Health);

            gameObjects.Add(gameHealthBar);

            foreach (var obj in gameObjects.ToList())
            {
                obj.Move(canvasWidth, canvasHeight);
                if (obj.IsDead())
                {
                    gameObjects.Remove(obj);
                }
            }

            foreach (var obj in gameObjects.Where((b => (b is Bullet))).ToList())
            {
                if (obj.Position.X < 0 || obj.Position.X > canvasWidth || obj.Position.Y < 0 || obj.Position.Y > canvasHeight)
                {
                    obj.Destroy();
                }
            }
            foreach (var obj in gameObjects.Where((a => (a is Asteroid))).ToList())
            {
                if ((obj.Position.X + obj.Radius > player.Position.X && obj.Position.X - obj.Radius < player.Position.X) && (obj.Position.Y + obj.Radius > player.Position.Y && obj.Position.Y - obj.Radius < player.Position.Y))
                {
                    if (!player.IsDead())
                    {
                        player.AsteroidCollision(obj);
                        obj.Destroy();
                    }
                }
            }
            foreach (var ast in gameObjects.Where((a => (a is Asteroid))).ToList())
            {
                foreach (var bul in gameObjects.Where((b => (b is Bullet))).ToList())
                {
                    if ((ast.Position.X + ast.Radius > bul.Position.X && ast.Position.X - ast.Radius < bul.Position.X) && (ast.Position.Y + ast.Radius > bul.Position.Y && ast.Position.Y - ast.Radius < bul.Position.Y))
                    {
                        gameObjects.Add((ast as Asteroid).Half());
                        bul.Destroy();
                    }
                }
            }
            if (player.Health <= 0)
            {
                gameOver = true;
            }
        }