I'd strongly recommend avoiding this game till they patch it a bit. The AI is basically nonexistent. I won two games in a row on normal just by blitzing the AI with summon spells (though you can do the same thing with normal units, given how little resistance the AI puts up).
I then bumped the difficulty for the AI and map up to 'Ridiculous', added another civ to make it more cramped... and repeated the same tactic. The AI isn't attacking me, even though I just crushed one of its neighbors with the same single summoner stack.
There's also a host of random bugs, some minor, some major.
Those actually bother me less, but if the AI presents no challenge of any sort, what's the point of playing?
I'm sure it'll improve in time, but unless you're really hard up for a fantasy TBS to screw around in, I'd recommend waiting until it's improved.