Ahead of tomorrow's 21.4 patch which brings us Hearthstone Mercenaries, Blizzard has published a list of known issues. They state that these will be addressed in future updates.

Quote From GnomeSayin

Hello all, we wanted to make you aware that there will be some known issues shipping with 21.4, which we intend to address in future updates. This post will house the known issues prior to launch, in all languages, and another post will be made if any unexpected live issues pop up.

The following are known issues that will be shipping with Patch 21.4, to be fixed in future updates:

  • Most Daily and Weekly Quests cannot be completed in Mercenaries. Only quests that require you to win a certain number of games in any mode, or take a number of turns, can be completed at this time. Quests can still be completed normally in the other game modes.
  • In Mercenaries, the general rule is that Taunt blocks an Attack, unless the Ability designates a specific target for the Attack (such as “Attack the lowest Health enemy” or “Attack the left-most enemy”). That said, at launch there are a few Treasure Abilities that will incorrectly ignore Taunt when they shouldn’t: Ogre Warmaul, Hysteria, Mass Hysteria, To the Death!, Blinding Rage 3, and The Beast Within 1-5.
  • Visual bug with the Diablo Mercenary’s Ability, Apocalypse level 3, combined with the Magma Horn Equipment, showing the wrong damage. The move applies the correct damage.
  • Visual bug with the Survival of the Fittest Ability, level 1, not showing the Ability’s Speed. The correct Speed is 9.
  • Rexxar’s “Mama Bear’s Claws” Equipment does not buff Mercenaries that are played before Rexxar, or to Rexxar’s left, during the placement phase. This is caused by the effects being read in play order, and from left-to-right. The workaround at this time is to play Rexxar before, and to the left of, any Beast Mercenaries you want him to buff.
  • Visual bug where the “upgrade available” indicator will sometimes continue to show after a Mercenary’s Ability or Equipment have been upgraded, even if there are not enough remaining Coins to upgrade that Mercenary any more.
  • Performance bug where playing Mercenaries for longer periods (around 1.5-2 hours) will cause lag and performance slowdowns, especially in devices with less RAM. The workaround at this time is to restart the client if that begins.
  • Visual bug where some tooltips and pop-ups are clipped off the edge of the screen on mobile devices.

Thanks for your patience, and good luck out there, Mercenaries!