I like the idea of making Hunter's hero power targetable from the start of the game, but it would be weird that Hunter's Hero Power would be so much better than both the basic Mage hero power and the Priest class card 'Shadowform'. Maybe it'd be more balanced if the text was "Can Only Target Minions"? That would make that card only tenable in control decks, as no aggressive deck would give up on 2 face damage per turn.
Plus it would differentiate the effect from an existing (wild) card:
Plus it would differentiate the effect from an existing (wild) card: