Board Thread:General Discussion/@comment-26873653-20160723035910/@comment-679780-20160827154650

Not yet, but Sonic 4's ending was unconclusive to what happened to Little Planet. Sonic Disabled the Death Egg Mk.II incased around Little Planet but he did not destroy it nor liberated Litle planet.

For all we know, Dr. Eggman has made the Death Egg Mk.II his personal TARDIS.