The deck is a swiss army knife, it has answers for literally anything in the current Wild meta.
The only downside of it that it is quite hard to play, you have to predict your opponent's play so you can always have a well-timed answer for it.

GUIDE

 Card choices & synergies

Removals: Earth Shock, Devolve, Plague of Murlocs, Hex and also
Zephrys the GreatThe ladder is swarming with Paladins and Warlocks, so we need transform effects to easily get rid of giant buffed mechs and cubed demons or an insane turn 5 board by Darkest Hour.

AOE: Volcano, Hagatha's Scheme and Earthquake
Good clears from small to large boards.

N'Zoth, the Corruptor package: I tried to make a good selection of taunts here to protect face and also get some value multiple times. 
Deathlord is a great early tool against aggro and can pull out some combo pieces from your opponent's deck. Don't play it against bigger decks if you don't have a removal in hand.
Khartut Defender is easily one of the best anti-aggro tools right now, you can ressurect it multiple times during the game.
Rotten Applebaum is less good but we need a third N'zoth minion for consistency so i included it. You can subsitute him for Sludge Belcher or White Eyes.

Heal pack: Healing Rain in my opinion is one of the best healing options in the game right now. 
Antique Healbot is still good, heal for 16 with Brann Bronzebeard.
Walking Fountain is just too good not to include it. Heals you for 8 and also removing some minions off the board. 

Tech: Since there are a lot of OTK combo decks and also some Highlander decks, Dirty Rat will be your saviour most of the time. Try to use it with Brann Bronzebeard and/or Zola the Gorgon for maximum effectiveness. 
And rule #1 of Dirty Rat: do NOT play him if you cannot deal with the outcome.
Golakka Crawler will come in handy since most aggro decks are playing pirates.
Acidic Swamp Ooze was originally included against Pirate Warriors, but found it useful against Secret Mages and Warlocks as well, playing Skull of the Man'ari.
Mages are currently the No.1 cancers of Wild so you will find Eater of Secrets useful.
Jepetto Joybuzz is also not a widely used card. But trust me, you can do some insane things with this guy if he hits the right cards. Maybe the only card which sucks if it gets hit by Jepetto is Walking Fountain. But that just rarely happens.

Yogg-Saron, Hope's End is a backup plan in case everything fails. Use Hagatha the Witch to feed him spells

The rest of my card choices I think are pretty much self explanatory for this kind of Shudderwock Shaman.

Matchups & Mulligan

Druid: Quite rare, it is almost always Jade, sometimes Embiggen aggro. If it's Jade it doesn't really matter because with some smart plays you can win it easily. So I recommend you to mulligan for Devolve or Reno Jackson because if it's aggro, you will not survive.

Hunter: I cannot really recall at least one time I played against Hunter. But I guess you should always mulligan for aggro, so Reno Jackson and friends.

Mage: Damn I so fed up with them. It is safe to say our worst matchup. If it is secret, go for heals and Eater of Secrets. You can also go for Acidic Swamp Ooze to prevent early Aluneth.
If it is Open the Waygate Quest, well...if you want to climb faster, you might just want to give up on this. I don't say it is unwinnable, you can control the game with some Loatheb and Dirty Rat shenanigans but they usually find a way to kill you with that damn portal.

Paladin: You will meet a lot of them. Hard mulligan for Devolve, Plague of Murlocs, Hex, Earth Shock, Zephrys the Great or maybe even Volcano. Take your time, you need to play your resources carefully and well-timed. If you can stop the devastation in the early game, you almost 100% won that game. But never underestimate them because of Divine Favor.

Priest: Not so common, but can be may types so it is difficult to say what to mulligan for. Most of the times it was King Togwaggle Priest so I think it is okay to mulligan for Dirty Rat. There are also some Dragon variations with Mind Blast or Inner Fire so always try to remove their stuff and stay healthy. I have seen some tryhard creative people still playing Big Priest, against them just look for your transform spells.

Rogue: Not so common as well, but it is always Odd Rogue. Search for your anti aggro tools. Golakka Crawler is great here.

Shaman: Always Even. Deal with their early board with removal spells, it is also good to keep an AOE like Hagatha's Scheme in your hand. Just keep their board in check and watch out for the Crackle burst damage and you'll be fine.

Warlock: Very common, and there are a lot of variations out there. Mostly it is Egg/Cube or Darkest Hour so probably the best card to keep is Plague of Murlocs because it is literally the only card in the game that can save you if they hit their combo on turn 5 (cheating out big minions is fun). Hex and Zephrys the Great are also important. Try to target their big demons so you don't have to deal with them twice. 
You should try to read your opponent's hand while mulliganing if they are keeping their first card (which could mean it is a Quest). If you are suspecting Mecha'thun, hard mulligan for Dirty Rat and his combo friends like Zola or Brann.

Warrior: Pirate time. Look for Reno Jackson, Acidic Swamp Ooze, Golakka Crawler, Devolve. Easy.

I hope this little guide helps you piloting this deck. It will take a lot of practice to be efficient with it, but trust me, worth it :)