Hearthpwn

Mulligan

All u have to do, is trying to keep or get Underbelly Angler, the quest and something cheap, don't keep the 3 or 4 mana cost cards. If u won't get Underbelly Angler try to get Murloc Tidehunter, he's going to help you a lot at the beggining, especially with Grimscale Oracle.

Gameplay

Gameplay isn't hard, for real. U just need to control the board and care for AoE spells, wchich can easily clean your board. Try to buff Underbelly Angler as much as possible, just to keep him unkillable. Try to complete the quest in the 5/6 turns. When Megafin will be your hand, try to wait for Scargil and easily fill you board with murlocs. With Sir Finley Mrrgglton u should try to get Warlocks hero power, u can easily become out of cards in 3rd or 4th turn.

Mage

 

U shouldn't put 1 hp murlocs early, because mage can easily get them down with his passive. U also should care for secrets and AoE spells like Arcane Explosion or

Blizzard. At all you shouldn't have problems with mage.

Hunter

Secret Hunter is a big problem for this deck. Explosive Trap is a pain in the ass, but still u can counter it with Coldlight Seer. U need good mulligan to win vs Hunter. Aggro is much easier to slain. Devolve and a lot of counter minions can control a board with no problem.

Warrior

Warrior has one deck which can destroy Murloc Shaman with no prob. Taunt Warrior. Minions with much hp and taunt are really hard to kill with 2 or 3 attack amount minions. U need to kill Taunt Warrior to win this matchup.

Paladin

Paladin, just like warrior, has one deck, which is hard to destroy. Divine shields, but now Divine Paladin isn't played a lot, so u shouldn't meet him on ladder. 

 

Rogue

Rogue with Kingsbane need a really good mulligan to get you. Deadly Poison and  Leeching Poison, and he can easily control the board. U need to care for this if u're playing vs Rogue. With else deck u shouldn't have any problem.

Druid 

Druid. We can meet somewhere Jade Druid, but it's not really often, he needs good mulligan to get Murloc Shaman down. Just because weak golems at the beggining u should have no problems with controling the board.

Warlock

Aggro Warlock is problematic, just because his hero power.  U need to try to control the board as much as you can with minions, and u can't let them die in trade. Discard Warlock isn't that hard to slain. Devolve counters him a lot. U can easily control the board with it and deal with the hero.

Priest

Priest is like free win. Big Priest, which is easy to meet on the ladder starts his fun at the 5th turn. To this time u have free hand to do what u want. You should spam the board with murlocs and try to get Murloc Warleader and deal with the hero with no problem.

Shaman

Elemental Shaman is also easy to slain. His game begins also at turn 4/5, earlier he can try to control the board a bit, but u shouldn't have any problems with these minions. Mirror match. Yeah.. u need to kill every murloc that he can put on the board. Or change them into something else with Devolve. 

Good luck, have fun. 

(Yeah, I don't care about my english mistakes, I'm sure u can understand this shiet ;) )