I've got about 74 hours in so far and here are my thoughts:
1) You need more customization of heroes. They're heroes, they need to be as customizable as possible. Right now, now matter what I give them, no matter what I equip on them... they look as boring as the first time I played them. Give them some starter equipment and change their appearance. Mount selection would be nice too. I mean, this is a successor to Legendary Heroes - where there could be mounts and equipment DID change appearance - so let's not go backwards. AND ALLOW US TO RENAME THE HEROES!
2) Figure out a setting or something so that the player doesn't start next to the sorcerer king. That makes no sense. If he was right next door, he would have been crushed. The whole story was he was too far and too small to worry about. Starting right next to the SK makes no sense and makes starting out a pain since all of you resources end up defending your one shard.
3) If the unit doesn't have a hero, ask before they activate a quest from a battlefield, inn, village, etc. The last thing I want is for my scout to start blowing quests because he's too weak to handle the 4573046485 monsters that spawn.
4) Allow customization of units. There was so much customization in Legendary Heroes that all units feel boring and cookie cutter. Allow us to customize equipment - including weapons - and have it reflected on the units. Allow us to customize them before they are built. Allow us to RENAME THEM!
5. Are quests supposed to give hero xp? I'm not sure why they wouldn't but they don't seem to be. I can do 5 quests and unless there is battle, my hero doesn't gain any xp.
6. More crafting recipes. More items - come on, give us some items for quests rewards!
7. In the storylines or whatever, you need to add some rudimentary text in the journal so we remember what we're supposed to do... I'm supposed to get what? from who? And take it where?
There's more... but I'll write that later.
This game has alot of potential. Don't ruin it with mediocracy.