I think one of the issues right now is that created units aren't terribly... exciting. One of the things that made MOM really awesome was the wide variation of unit abilities. I believe that attributing these abilities to the items in game will greatly increase the fun of unit design. Here are some abilities that should have a place in Elemental, and make the tactical game more fun.
1. Magic damage. Crystal (or shard) based weapons? Magic damage may or may not ignore some percentage of defense. Perhaps it ignores all "magical" defenses (buffs? uber-units (Dragons, Heroes?). Also, I one of the things that made MOM fun was the weapon-immune units, which were weak otherwise. Minor summoned units, like Wisps or Imps, could be weapon immune, with low HP, and could only be damaged by magic. There could be variations of this for each type of elemental damage. (Fire sword, Magic Sword, etc. . .)
2. First Strike. First strike units get to do damage first, regardless of whether they are attacking or defending. First strike versus First Strike is like normal. This could be a cavalry ability, or perhaps an ability on a mid range "Superior" sword. Or both, of course.
3. No retaliation strikes. This could either be on short-ranged "ranged" weapons (throwing knives, axes), or on exotic melee weapons (Scythe?). No counter attacks.
4. Polearms. Polearms do double damage to cavalry and 4-legged units (dragons, wolves, bears, other beasts).
5. Magic immunity. These units would ONLY take "normal" damage. No buff damage, no spell damage, and do not suffer from dragon fire or other special creature damage. I'm thinking the Human "Crusader" unit from MOM.
6. Special metals. I loved the aspect of admantium and mythril resources in MOM. Put "special" metals into Elemental, make it so that only the linked cities can produce units with those forms of "enhanced" swords/weapons. These weapons would do generic magic damage, and be 10-20% more effective than standard. Also, special woods would be nice, too. I'm thinking witch-wood from the Dragonbone Chair. The Witch-wood resource would unlock enhanced staves, bows, and shields.
7. Civilization specific weapons (or armor). How about only Pariden can produce Recursive Bows, and Kraxis gets special Katana that are first strike? Or another civ gets battle hammers that endow magic immunity? One of the best parts of MOM was that you had a general idea what each enemy race would be good at; curve balls now and then would trip you up, but as a single player game the "flavor" was more important than strategic balance. Plus, it is A-Okay for some civilizations to be worse warriors than others. Human Crusaders > Halfling Slingers, but you could produce twice as many slingers, and the halfling economy was generally better).
8. More mounts! Make them rare, too. Elephants (+dmg, +hp, no extra speed). Griffons (lots of speed, -hp). Maybe a high-level quest that gives you a dragon ranch (1 dragon per 10 turns? or Dragonkin (uber, +dmg, +hp, +speed, expensive) (mini-dragon mount?). Camel (extra speed, cheap). Dolphin (can swim). Centaur (requires no population, the mount is the unit).
9. I'm sure there are 100 more possible concepts. Units that regenerate X HP per battle round. Units that do not heal, ever, perhaps as a result of a special idol produced by death-worshipping cultures (ghouls! skeletons!) . Units endowed with elemental immunity, maybe even units that are healed by a certain type of damage! (Fire spells heal units carrying the fire totem). Lucky units (+5% to all abiliies).
10. And of course, the combinations of above. How do my magic immune, pole armed foot soldiers perform against your adamantium wielding, first strike, elephant riders that regenerate 1 hp per round?
As it is, the units in Elemental seem a little bland. A little bit like the creatures from Spore, where it really didn't matter how many feet you installed, or what kind of weapon you attached to an arm. The numerical stats of MOM, although an integral part of the battle system, would have been extremely boring without the huge range of "special" abilities, some of which were fairly trivial (halfling's luck). Absolute numerical balance isn't necessary, as long as the various combinations have valid responses. That's where the strategic mystery, and fog of war, come into play.
Please please please; either make these abilities happen, or reassure us that they have been part of the plan all along, and simply haven't been inserted yet.
For giggles, here is a list of MOM abilities:
Special Attack Types:
Breath (Calculated before melee damage occurs, only used when attacking)
First Strike (Calculated before melee damage occurs, only when attacking)
Gaze (Calculated before melee damage occurs, works when attacking or defending)
Lifestealing (Calculated during melee damage, i.e. in addition to standard damage, attack or defend)
Poison (Calculated during melee, attack or defend)
Ranged (Replaces melee, attack only)
Thrown (Before Melee, attack only)
Touch (During Melee, attack or defend)
These special attack types were combined with damage types, which included the following:
Elemental (all types)
Death (resist or die, good for "Gaze" attacks)
Chaos (low damage, but ignores defense)
Phantasmal (ignores non-magical defense)
Armor Piercing (ignores 1/2 of defense)
Stoning (resist or turn to stone. Can be dispelled, unlike "death")
Charm (resist or turn sides!)
Wall Crusher (extra damage to buildings, siege weapons)