I finally beat the game. Awesome story mode for this game. So much spoilers I won't mention for now.

Adventure Mode gets really, really hard in some places. I only just unlocked the final tier of missions that I haven't done yet, but there are three previous missions that I simply cannot get the A-Rank rewards on. Volga and Argorok in one keep room, and you have to kill them both without taking too much damage. Seriously?!