void OnCollisionEnter2D(Collision2D other)
    {
        EnemyController e = other.collider.GetComponent <EnemyController> ();

        if (e != null)
        {
            e.Fix();
        }
        FastEnemyController f = other.collider.GetComponent <FastEnemyController> ();

        if (f != null)
        {
            f.Fix();
        }
        GhostController g = other.collider.GetComponent <GhostController> ();

        if (g != null)
        {
            g.Fix();
        }
        Destroy(gameObject);
    }