Ditto.  Just add kick ass Hero units you could customize with spells and artifacts and you have my list as well.

Sammual

I know everyone's thinking "apple pie," but my mom's trump treat was her pumpkin pie. Oh wait, that's a matter of taste, innit?

Seriously, though, I hadn't even considered an 'impossible standard' problem harming Stardock revenue (I gave up regularly reading game sites shortly after Games Domain stopped being By Gamers, For Gamers and started being By Marketers, For Mindless Consumers). There's definitely a self-interest value for us 'niche game' folks in seeing Stardock succeed with this project. It increases the chances that Stardock and/or an admiring competitor will do more work for the same underserved audience.

^ ^ ^  What he said. 

I loved that in the reverse.  Casting heal spells on weakened squads made them stronger

Having the unique ability to enchant an entire set of items with "multiple" powers each.

Also selecting unique "Abilities" at the start of the game, which further distinguishes you from other summoners.

Choosing your own "Race" at the start which further allows singular distinction.

Being able to conquer the entire game with one mega powerful "Hero" unit. (I did this many times with death magic)

Being able to conquer the entire game without ever expanding outside of your initial starting city.

And one of the coolest options i recall was the "choice" between capturing a city or razing it.  (This was such an awesome feature)

The nodes were so enchanting, something akin to being captivated by an hypnotic sirens song. I never captured them out of neccesity, rather i just took them because they sparkled. I just "HAD" to have that lovely sparkling addition to my territory. (Dr. Evil laugh here)

Yes, finding new spells and monster "Lairs" was awesome. Lairs in particular since you would often times find something so powerful it would stomp 5 normal units without breaking a sweat, and most times you would have to wait till either later in the game or organize an entire "expedition" specifically for the purpose of taking the monster "Lair". That feature made me giddy every time.

The list of "cool factor" in MoM is so inexhaustible that i could write 500 pages on it without getting bored in the slightest.

I used to do the "all ability" thing as well.  I would go for dwarves.  Get a adamantite hammerhand pump going.  You can pretty much smash everthing except draconians because you get hammerhands so early.

In terms of atmosphere--I remember having chills go down my spine the first time I cast a mass death spell and the world faded to darkness.

man, flying monsters are a pain.

but not as much as the ones that can only be hurt by magic.

The infinite replayability, thanks to the variety in maps, quite well-balanced races that were really different, the vast array of spells and units, going far beyond the overly used "humans, elfs, orcs"

And of course the good balance between different tactics even if some at times could seem overpowered, e.g. would you go for a huge army of strong standard units, expensive beefed up heroes, massive spellcasting or summoning powerful creatures?

Also worth noticing is the many, many types of unit characteristics, making things much more interesting than the usual rock-paper-scissors. Yet at the same time most characteristics were very straightforward to understand.

And if you want to go on, the simple production vs food system, the bonus tiles and magical nodes were pretty amazing elements as well.

Most of the MOM copies / clones I've seen over the years either failed in terms of variety (way too few spells and/or units) or in terms of combat mechanics (almost random battle outcomes)

AoW was different in a number of areas.   For starters, its maps were built like HoMM, not like MoM.   They were noisy with little things to be found, and cities were not as influenced by their  location  as MoM cities were.  

City building did not have any sort of picture interface that really gave you the  'feeling' that the city was build built.  Sure, you had similar building from an "On paper" point of view, but it still 'felt' too dissimilar to be the same.

There was not  much in  the way of alternate planes.    There was an underground, but since map construction  worked like HoMM, the underground was very limited when compared to Myrror.  The undeground had specific pathways that  forced  your  movement, unlike  Myrror which was just as open as the 1st world.  It wasn't  a "sub-level" and the freedom of movement and potential ability to research into moving between the worlds at will, the  myrror world could resurt in some very different tactics.  So I'd have to disagree with multiple planes, because AoW doesn't have it. It has "underground" and thats constructed in a way that doesn't let it be a substitute for MoM's system.

The magic seemed to be too heavy on the battle spells, and the non-combat spells were rarly very useful.  I mean, "global" spells had to encompass so much, and yet it did not end up with the kind of diversity that MoM seemed to carry.  In a  way its kind  like  Megaman weapons...  They  had the same 'ideas' but it requires a good blance of abilities and cost before you actually *want* to use them.

The wizard was fairly limited in range as well, and so if you basically had two tactics: turtle until you could cast spells in enemy domain, or build a huge army and sweep.  You couldn't really rush the spell tree and go in with heavy  magic blazing, because you wouldn't be able to cast spells far enough, or your wizard would be at serious risk.

Magic Spheres were not like  MoM's tomes.  Magic Spheres let you pick your school of magic, or even up to 3 specialties, but that was the depth of it.   Magic tomes in MoM influnced not only the magic  you  cast, but the amount of that magic you could research.  There was a tactic for taking only like 1 tome in "life" to gain access to guardian or something like that.  This also effected spells you could trade or buy,  since if I recall right you could pretty much buy and spell you wanted in  AoW if you could find somebody willing to sell it.   Spells were directly  related to your skills  and abilities as well, since it cost  tomes to gain "artificier" and such.

Of course this is all opinion.  I'd say that most of us agree that AoW did not "FEEL" like MoM.  MoM felt like Cizilization with armies and magic.   AoW felt like HoMM with economy, diplomacy, and a "main wizard" type character.  I'd agree it was close.  When I played AoW I kept noting things  that  were more or less a direct rip from MoM.   But the general game-style was too far  off to be a sequel.

AoW is not at all a worthy successor. MoM does not have a worthy successor, which is why so many people have such high hopes for this game.

landisaurus had some great points, I'll add a few of my own:

• The "character creation" at the start of a game in MoM is still unparalleled (in strategy games anyway) to this day. It is more complex and compelling than many RPGs and has enormous impact on how the game will play out.
• The huge variety of items and heroes (and the fact that even the same hero was often slightly different each time due to randomized abilities) made you want to play the game over and over again just to see what crazy things you might find/create.
• The combinatorial explosion of 14 extremely unique races (5 of which are special and only on Myrror), over 200 spells and the fact that you are limited to 11 spell books of various colours (fewer if you take special picks like Myrran) leads to an amazing variety of strategies simply unmatched by any other game I've ever seen.
• The vast differences between the races cannot be overstated. From the swimming lizardmen to the flying draconians and the spellcasting dark elves... you get the picture.

FFH2 as in the Fall From Heaven Civ IV mod?

Yup