Cool game, the card art was good.
I think you could start of with 3 mana, instead of having to skip the first round every time.
I beat all 3 on normal difficulty, although the difficulty is just the enemy having more hp, which wouldn't be harder for 1 and 3, only for the second battle I won with 0 hp, but that could also be done it would just take more time.
Some cards indicated obtaining some build points, but I didn't figure out what they do, (I didn't play the tutorial, mainly since it got added later and people were complaining they didn't know what to do so I wanted to test myself, and I'd say it was a standard card game, intuitive if you've played several before), also not sure what "going home" did, except that some cards got (mad) bonuses for it.
The exclamation points probably weren't the best way to tell the player that they can be hovered over, I think question marks would be better for that (also probably more yellow then orange/red).