Well, just finished up my first game yesterday after about 300 turns, which was ended quite fast by my super-upgraded Flying Line Galleus that I got from a quest and which single-handedly destroyed two of my opponents and captured their cities in three turns. Now for the demands:
Basic tooltips that are actually useful. Like has been said, that actually gives you needed info and not just "costs 2 mana to upkeep".
A "keep playing" button... I wanted to see what the other planes were like!
Some sort of infopedia like Civ has; as for now, I found some "Ancient ruins" and built a city next to them, but the game ended before I could expand the city and thus have any idea what they actually did. As ffor now, I'm mostly stumbling around blindly and making building decisions off information I can infer from "potential buildings", tooltips and guesswork, which doesn't feel like a good way of doing things. For instance, I had no idea I coiuld build a casino on the Elven village until it gave me the option to do so, and I still didn't manage to build a Flying Line Galleus myself despite apparently having all the requirements for it. Tech trees PLEASE!!!
Less random spell research - I just picked whatever seemed appropriate without knowing where it would lead or how to get to the useful spells.
Also, on that topic, less useless spells that I never use. I played as a researcher, and by the end of the game I had like 30 spells and had used maybe five of them more than once. (Mostly Prosperity to expand cities and Reconstruction to heal my FLG.) As has been said, it feels like playing Civ with some magic thrown in, and you're not exactly a "Master of the Arcane" if it takes you a full turn to conjure up some wolves or even just throw a healing spell - I had the "halves casting time" enchantment running for most of the game and I STILL felt underpowered. Meh.
Ability to sort the spell window after casting cost, god, name, school or order researched - as of now I had to remember in what order I researched the spells to be able to find them again which is just a stupid design choice. What happened to sortable lists and actually useful research windows?
Ability to destroy buildings, or at least not turn them off! As of now I just kept my military buildings off almost all the time because there was no penalty for doing so, and since I still could use their abilities, why ever keep them on? In the same vein, I built a Silver Mine in my capital, and only much later did I realise I wanted a Silver Smithy there instead... and couldn't destroy it since you can't tear down your capital or even move it. Seriously annoying in a game with limited building space to not be able to make more of it...
Ability to use water tiles along the lines of Civ, and actually do something with them.
Some info on terrain types and movement costs, and what happens if you build on them. Since my first city was next to a lava field, I assumed I couldn't do anything with it... until I realised it was perfectly acceptable to build a farmstead with little fields and animals right on top of it. What's up with that? Same with building stuff in a snowy hillside - who manages to farm the land there as efficiently as in a plainside river valley? Weird and strange.
Better diplomacy as noticed above - as for now I just kept at war with the AI for almost the entire game except at the start, when me and my undead neighbour teamed up to defeat the Koatl queen - after which she immediately declared war on me and kept that for like ever. And even when she only had her capital left, she had the audacity to demand both a peace treaty AND money from me! Like I'd accept that - when the AI demands peace, it's more a sign of their weakness and that they don't want to fight anymore, which is a giveaway that you can easily defeat them. (Which I also did with the aid of a catapult, a bunch of super-trained Skeleton Warriors and my FLG with regeneration and fire/life/death-extra-damage-enchantments. That was also immune to death damage. Which they shot at me. Great success!
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Less random and strange quests. I hear this is a problem with the temples, but I conquered like 80% of the Medium world without finding a single temple site, so I didn't much care for it. But still, would be kind of cool to get something like that.
Ability to move your capital.
Ability to convert conquered cities to your own race a la Heroes VI. As of now I captured my undead neighbours and ended up using almost exclusively undead units for the rest of the game despite being human, and nobody seemed to care. Shouldn't this be kind of changed somehow?
Ability to tell what damage a spell could cause, and what if anything the unit is immune or resistant to. Would be quite convenient.
And finally, some way of telling how to increase the population of a city, what causes it to expand and how long until that happens. For one of my cities I slapped three food enhancement buffs along with lots of farms and boosters, which caused it to produce like 150 food per turn and thus the majority of my empire's foodstuffs, and for another I just slapped Prosperity on it and hoped to get lucky.
I like predictability in my games, and not random luck, guesswork or plain inability to know what's going on in your game. Most of the above reflects just that - no info meaning no way of knowing, and as they say; knowing is half the battle. This game has potential, but also a little too many flaws to be really great at the moment. Go get some of the mentioned issues, and it just might be something one wants to come back to and play again and again, instead of just occasionally like now. But still, it's good. Toodles!