First of all i want to say, that english is not my main language so probably I will make grammar mistakes, sorry.
As I promised for 50 likes I will make a guide how to play this deck and mulligan. Let's start with mulligan.
Vs Face decks:
Decks like: face hunter; crow mage.
You want to mulligan cards like: Feral Spirit; Brrrloc; Murloc Tidecaller; Knife Juggler; Rockpool Hunter;
You have most chance to win against face decks is to rush them first.
Vs token decks:
Decks like: Odd paladin; zoo; tempo rogue.
You want to mulligan cards like: Unite the Murlocs; Knife Juggler; Lightning Storm; Primalfin Totem; Murloc Tidecaller;
Your goal is to clear board as much as posible and stale the game.
Vs Control decks:
Decks like: Taunt druid; Hand druid.
You want to mulligan cards like: Unite the Murlocs; Hagatha the Witch; Primalfin Lookout; Primalfin Totem; Murloc Tidecaller; Ice Fishing;
Your goal is prepare for long battle and outstand control deck with your combo.
Vs Combo decks:
Decks like: Cubelock.
You want to mulligan cards like: Unite the Murlocs; Spellbreaker; Hex;
Depends on cards you get, you can try out stand them or rush them down. If they don't have doomguards it's betters to outstand them.
Early game (early game is game before you complete the quest):
Case 1: You fight against face deck (face hunter).
Drop your quest and try to get agresive card. Trade when its necessary try to go face as much as posible. These match ups are unfavorable for you.
Case 2: You play against token deck.
At this match up you try to stall the game. If you have a coin is good to start with it and summoning Primalfin Totem or quest and Murloc Tidecaller or in some cases you can summon Knife Juggler but be sure that they wont kill him immediately. Your goal is to trade minions and get board control.
lighning storm is most valuable card in these matchups so dont waste it for 2 minions wait till good moment. Stale the game till you can summon Megafin if you are alive and you summoned Megafin you probably won game.
Good combos: Knife Juggler + Primalfin Totem; Knife Juggler + Murloc Tidehunter; Murloc Tidecaller + Rockpool Hunter
Case 3: You play against control deck.
At this match up relax and wait for late game. Always try to have 3-5 minions on the board do not overdo it. Wait till you complete the quest and get Hagatha the Witch.
Hex is the most important card so don't waste it.
Continue in late game guide
Case 4: You play against combo deck.
These matches are hard you have to rush them and have juice for longer game. But early game is more forgivable so you can keep the quest. Its good to start with coin + Knife Juggler. If you have perfect early game you can ignore quest for few turns and put it on second turn or thrid turn.
Most valuable cards: Murloc Warleader Gentle Megasaur these cards can generate most dmg.
I started record my statistics from rank 10, my goal is to reatch legendary rank with this deck.
At this point i was rank 7:
I felt kinda lucky in many matches :D
To be continued...
For 150 likes i will create a video with my gameplay.
I had small break and now I am back. I edited deck to be stronger against control match ups because now i am at rank 4. Vs taunt druid you should hex taunts before they can revive hedranox then they have 66% chance to revive frog not hedranox. Vs cubelock you hex demons.
-2x knife juggler -1x spellbreaker +1x hex +1x earth shock +1x acidic swamp ooze
Making deck more tempo like mainly because of paladins.
+ 2x nightmare amalgan/- 2x primalfin totem
+ 1x Fire fly/- 1x feral spirit
+ 2x knife juggler/- 2x hot spring guardian
+ 2x brrrloc/- 2x bluegill warrior
+ 1x Spellbreaker/- 1x healing rain