Hearthpwn

Not criticizing this deck in particular, but I found this deck doesn't work on a fundamental level.

The biggest issue is mage doesn't have tempo secrets like hunter, yet the stats of kabal lackey and kabal crystal runner all encourage an aggressive playstyle. Secondly, mage secrets are just bad, easy to play around and redundant, like mirror image and potion of polymorph triggering together on a 1 drop. The third problem, medivh's valet and ethereal arcanist, all work against your secrets actually being triggered. In a way, you are punished when your opponent plays into a secret. Ice block is too late game of a secret to work very well. The fourth problem is card draw. The sheer amount of secrets you need play and the cost reduction means after turn 4 you can play your whole hand and there's so little space to actually fit card draw in this deck. This is really bad because all the strategy of which secret to play just goes out the window when you only have 1 secret in your hand and you need to play it to keep up the tempo. This leads to the fifth problem. After turn 5 the cost reduction don't even matter. You just end up playing poor minions for a pay off of a 0 mana 5/5 which is nothing in a meta where players are making 1 mana 7/7s.