public override void Update(GameTime gameTime)
{
MoveRandomly(gameTime);
Move();
base.Update(gameTime);
// Remove object after a certain amount of time if it's off screen
timeAlive += gameTime.ElapsedGameTime;
if (timeAlive >= MAX_ALIVE_TIME && (Position.X < -Width || Position.X > 720))
manager.RemoveObject(this);
}