Had quite a bit of success (10W-13L) with this deck against seemingly old archetypes without almost any new cards(Pirate Warrior, Secret Mage, Odd Paladin, Mech Paladin). 

So, I'd say it's quite a success. 

Disciple of Galakrond and Shield of Galakrond can upgrade Galakrond at least once quite reliably. It's a bit less reliable with Time Rip, but it's nice to have an unconditional removal. To be honest, could never upgrade him to third stage. However, even at stage two he's quite good and his hero power(and a bit of luck), helped out aginst some more control oriented decks(Reno mage and Handlock).

Play Lady in White only if you are feeling comfortable on the board and health wise. It should provide a buff for at least 1-9 attack to your minions in deck.

Chronobreaker is a bit slow(still considering him in a deck), but can serve as a thread for aggro decks. Drop him if your opponent can't burst you down or throw a lot of damage at your face or, if you think that it's an explosive trap your opponent has.  

Kronx Dragonhoof is a lot better after you become Galakrond, so use him sparingly, because you will probably be upgrading your Galakrond really slowly.

This deck has only 4 original spells, so Counterspells might be a problem, but with so many minion AOE, you should be fine. 

Use Omega Medic sparingly, since it's your only serious source of healing, when you become Galakrond.

Muligan for Wyrmrest Agent and at least one dragon. [Hearthstone Card (Duscbreaker) Not Found] is a another good opening option, if your opponent is Warrior, Mage or Paladin.