Top priority for me would be even better game mechanics, I dont care about story, walls of text or nice pictures very much.
In one word, I like more synergy in the game!
I really like the way this game offers strategical and tactical options, like when you think pffff spiders and snakes until you find this ridiculous artifact, which adds like +15 to spider attacks and increases their speed and you think wtf, I might test a spider combo out.
Or when you see all those slow dwarven units until you find artifacts which boosts them immensly and suddenly you can see a nice strat with them.
Or the humans with the guardsmen/royal griffins being commanders of the bowmen and swordsmen to boost their moral.
Those were the moments this game went from great to totally awesome for me
Also an option at the start of the game to have some COMPLETE sets of artifacts in the game would be nice. I've never managed to get a full set (despite some minor one's). This is always pretty frustrating imo.
An option to buy or otherwise change to a new repertory of artifacts/troops at useless merchants would be nice.
I'm totally fine with the looks of the game though.