The following is a changelog of differences from Fallen Enchantress to Fallen Enchantress: Legendary Heroes. It doesn't include a wide array of performance improvements (Intel was nice enough to come onsite and do some profiling on LH with our developers and turn out some good results); but it should give an indication of the tweaks and additions the game contains.

Features

Swarm- All melee units get a bonus to accuracy and damage for every ally that surrounds the enemy they are attacking.

Fame- Clearing lairs, completing quests and building some improvements gains Fame for your faction.  When enough Fame is earned champions will offer their services to you.  Two champions are always offered and the player can only select one.

Champion level up system.  Champion now have access to a trait tree that they can pick from when they level up.

Produce resources in your cities.  Instead of constructing improvements and training units you can set your cities to produce additional wealth, research, growth or mana.

Huge Map type.  Our biggest map size yet.

Steam Integration- Cloud saves of games, lots of new steam achievements and automatic patching.

City Count Penalty- You now get an Unrest penalty in all of your cities based on the number of cities in your empire (the more cities, the more unrest).  This makes Unrest a bigger issue for larger empires and helps equalize the production and research of large empires vs small empires.

Food Growth Bonus- Cities with access to more unused food get a growth bonus.  This way high Grain cities can not only grow to a larger size, they will get there faster than low grain cities.

Lots of new tactical arenas.  In general enemy armies start a lot closer to each other so the battle can start immediately (and ranged units are in immediate trouble if you don't bring units to defend them).

Added a Production Pace slider to the game setup options.  Player can now modify the research pace and the production pace seperately.

The World Difficulty slider now effects the level of monster in the world.  Set it down to have monsters start out at a lower level than normal, or up to have them start out higher.

Each faction has a special ability

Altarian- Rush ability allows them to use their attack to go again

Ironeer- Guarded Strike ability allows the unit to attack for half damage but puts the unit into a defending stance

Kraxis- Fortify ability increases the Dodge and Accuracy of units in fortified tiles (as it was in FE)

Mancer- Mancer units get +1 Movement and +1 accuracy per level

Pariden- Soul Spark does lightning damage at range, but costs mana

Quendar- Flame Tongue does fire damage to an enemy within 1 tile

Tarth- Double Strike allows the unit to attack twice at -30 to Accuracy

Trog- Berserk ability puts the unit under AI control , but the unit gets to go immediately and gets a bonus to attack and Initiative.  Berserk units can't cast spells.  Berserk doesn’t do damage per round anymore.

Urxen- Urxen units get double the normal swarm bonus

Wraith- Wraith Touch ability drains a small amount of life from an enemy within 1 tiles and gives it to the attacker

Weapon types have special abilities

Axes- Cleave ability allows the attacker to strike up to 3 enemies that are adjacent to him.  Cleave damage can be modified by traits. (axes still backswing)

Spears- Impale ability allows the attacker to strike an enemy and an enemy on the opposite side. (spear still ignore a percentage of armor)

Club/Hammers- Crushing Blow ability does double normal damage, but the attacker loses their next action.  Crushing Blow damage can be modified by traits. (blunt weapons still have a chance to knock victims prone)

Swords/Daggers- Swords and daggers allow the unit to counterattack when attacked (as in FE)

Shields- Any unit with a shield can shield bash an enemy, doing normal damage and knocking them back a tile

Added Crossbow class weapons.  Crossbows are ranged weapons that are slightly slower than normal bows, but they allow a special attack called power shot that allows them to fire through multiple enemies in a straight line (the amount of enemies depends on the type of crossbow)

Spells/Abilities can now be dodgeable (if this tag is set on spells like Throwing Knives, Hurl Boulder and Spit Acid the caster must hit the victim for the effect to take place)

Added support for the Line range type- Spells and abilities can now target a line of tiles at a specified length

Added support for the Adjacent range type- Spells and abilities can now target a selection of units next to the caster but adjacent to each other

Added support for spells that are multiplied by the count of units in the casters stack- This is used by abilities like the Quendar's Flame Tongue ability so group of trained units can use spells.

New Monsters

Banshee- Undead ghost that is immune to physical damage and attacks with the Horrific Wail spell, which damages all enemies

Brood Hunter- These half spider creatures are fast and armed with a longbow.  They are usually found with spiders than immobilize and weaken enemies so they can pick them off at range.

Brood Warden- Armored half spider creatures that are even better defenders to Brood Wardens and can quickly close with their pikes and high movement.

Cindercorpse- Burning undead corpse with the Inner Fire ability (ranged fire attack)

Hergon- Half wild boar, half brick wall.  Hergons have high movement and everytime they attack a unit they knock it back a tile, messing with defense lines and attempts to control the battlefield.

Hergon Sow- A smaller version of the pushy male of her species.

Lich- Powerful undead spellcaster.  As if dark wizards weren't bad enough, they get worse when they die.

Lightbringer- A strong Spirit equipped with an Angelic Longsword and the ability to use Soul Spark and Blinding Light

Skeleton (3 variations)- Skeletons are weak but they often come in large numbers and with dangerous weapons

Wisp- A weak Spirit able to use the Healing Light and Soul Spark abilities

New Champions- All the champions have been redone for Legendary Heroes to make them more unique.  But the following champions are brand new and can be gained through quests or they may offer their services.

Raza the Wild- Wilding Shaman and powerful mage.  He has access to the same Coal Stones ability as his wild kin.

Kasst- Fast Brood Warden warrior with an innate resistance to magic.

Tuatha- Troll hero with innate regeneration and a love for giant weapons.

Huhrus- The Ogre from the FE quest, but now he is a champion so you can equip him and have him learn traits as he levels up.

Gallowman- An undead master of necromancy.

Nen Ratcatcher- A darkling shaman, master of death magic and with his brothers aptitude for Shrink spells.

Ascian- A great cat and former assassin for Lady Umber.

Mausolos- The tomb guardian, a massive stone golem and defender with the ability to cast Death Ward in battle.

New Spells/Abilities

Blinding Light- Surrounding enemies must save or be blinded.  Special ability of the Lightbringer.

Blink- Teleport to any location on the battlefield.  Ability granted by the Flickering Ring.

Break- Assassin attack that does normal damage and removes the targets defense for 3 turns.

Call Lightning- Does lightning damage to all units within the radius.

Channel Lightning- Does the units attack as lightning damage.

Command- Commander ability that allows another unit to take a turn immediately.

Consume Spirit- Special ability of Gallowman, does damage and grants mana if it kills the unit.

Cure Plague- Used to complete a quest.

Death Ward- Tactical version of the strategic spell with a limited duration.  Allows a unit to be reborn if he dies within 5 turns.  This is a special ability of Ancient Grave Elementals and Mausolos.

Eviscerate- Assassin ability to attack an enemy for an automatic critical hit.

Guard- Defender ability to add a unit's defense to up to 3 adjacent allies and it puts the unit in the defensive stance.

Gust of Wind- Blows back up to 3 enemies that are adjacent to the caster.

Healing Light- heals all allies within 1 tile of the caster.  Special ability of Wisps.

Inferno- Tactical version of the strategic spell that surrounds the caster with inferno tiles and damages anyone in them.  Special ability of Fire Elementals.

Inner Fire- Does fire damage at range.  Special ability of Cindercorpses.

Lightning Bolt- Does 10 lightning damage to all enemies in a 5 tile long line.

Lightning Form- Unit transforms into lighting, shooting through 5 tiles and damaging all enemies in those tiles.  Unit ends the action at the end of that line.  Special ability of Ascian and Bragni.

Rain of Arrows- Bow only attack that strikes all enemies within the effected radius.

Raise Skeletal Horde- Summon 9 different skeletons into battle.

Raise Skeleton- Summon a lowly skeleton.  Raise Skeleton has no casting cost.

Rescue- Defender ability to switch places with an ally in tactical combat and take another action.

Riptide- Do damage to up to 3 adjacent enemies.

Shadowshift- Assassin ability to Switch places with an enemy and take another action.

Summon Air Elemental- Summons and Air Elemental, if used in Tactical it knocks back enemies around the elemental.

Summon Crag Spawn- Summons a Crag spawn and dumps stinking mud in all tiles around him, reducing movement of anyone in them.

Summon Delin- Summon Delin, the Pyre of Man for 3 actions.

Summon Grave Elemental- Summons a Grave Elemental, if used in tactical all surrounding allies receive Death Ward for 5 turns.

Summon Ignys- Summons an Ignys.  If used in tactical all surrounding enemies take some fire damage.

Summon Lightbringer- Summons a Lightbringer.  If used in tactical all surrounding enemies must save or be blinded.

Summon Wisp- Summons a Wisp.  If used in tactical all surrounding allies are healed.

Wall of Fire- Added a tactical version of the Wall of Fire spell.  It sets fire to a line of tiles 7 long.

Withstand- Defender ability that makes the unit immune to magic damage for until its next action.

New Traits

Abjuration- Unlocks the Cloak of Thorns, Protection from Cold and Protection from Fire spells

Aeromancy- Unlocks the Gust of Wind, Lightning Bolt and Obscuring Fog spells

Armor Proficiency- Defender ability to carry additional weight

Axeman- Warrior ability to do increased damage with the Cleave ability

Bleed- Assassin ability to have damaged units take damage per turn, traits can modify the amount of damage done by bleeding.

Compassion- Mage ability that increases the amount healed with heal spells

Geomancy- Unlocks the Gift of Iron and Sunder spells

Ghost- ghosts take no damage from physical attacks

Greater Necromancy- Unlocks the Raise Skeletal Horde and Horrific Wail spells

Hydromancy- Unlocks the Gentle Rain, Frozen Bones and Riptide spells

Immune to Swarm- This unit is immune to its enemies swarm bonuses.

Innovation- Commander trait that gives the player an immediate +100 research

Missing Finger- Injury that reduces the amount of accessories this unit can equip

Necromancy- Unlocks the Raise Skeleton spell

Pack Tactics- Monsters with this trait get double the normal swarm bonus (typically this goes to wolves)

Pyromancy- Unlocks the Soulburning and Incinerate City spells

Reap- Unit gains life whenever he damages enemies, traits can modify the amount of life received

Revenge- Unit gets +1 attack each time it is struck in battle

Savant- Mage ability that reduces casting times by 1

Spirit- spirits take half damage from physical attacks

Tinker- Unit can equip an additional accessory

Volcanic Rites- Mage trait which increases the amount of damage from fire spells

Wealth- Commander trait that gives an additional 500 gildar when selected

New Items

Amethyst Collar- Can be used to tame a twisted unit to your control.

Angelic Longsword- Longsword that does additional damage vs Undead.

Bacco's Hammer- A very crude hammer, but it gets better as the wearer levels.

Blessed Hammer- Hammer that does additional damage vs Undead.

Brood Cuirass- A spider curiass that retains some of its makers spell resistance.

Brood Vambrace- A sharpened vambrace that improves the units attack.

Butcher's Axe- Heals the wielders life each time it strikes an enemy.

Crossbow- Ranged weapon with a special attack that fires through up to 3 enemies.

Dagger of the Leech- Heals the wielders life each time it strikes an enemy.

Flickering Ring- Allows the unit to cast blink once per battle.

Guardian Blade- Short sword that does double the normal counterattack damage.

Heavy Crossbow- Ranged weapon with a special attack that fires through up to 5 enemies.

Padded Vest- A very cheap vest, better than nothing, but not by much.

Perfect Crossbow- Enchanted crossbow with increased initiative and attack.

Ring of Ash- Increases fire damage of the wearer's spells.

Ring of Calling- Increases the level of the wearer's summons.

Ring of Restoration- Increases the potency of the wearer's healing spells.

Ruined Chain Shirt- Still being worn by the skeletons of elementals, and starting sovereigns.

New Quests

Random events are more common in Legendary Heroes including several large game effecting events.

Ascian- You discover ancient tomes about Lady Umbers assassin, you can follow the trail, but it's a dangerous path.

Bacco the Beggar- A drunk challenges you to single combat.

The Banshee- A necromancer attempts to save his wife form dying.  But the life his magic gives her is worse than death.

The Mausoleum- A recent storm has opened up a crypt that has been long closed.

Ongr the Unbound- An abomination has been loosed in the world.  Although armies would do well to avoid him, the one that kills him can claim his sword.

The Riddle- Mimbly is back, and he isn't any less insulting.

Night of Haunted Dreams- On the night of Shirayn's resurrection the veil between this world and the next is drawn back and the dead flood into the world.

The Plague- A plague has spread across your empire.  Will you deal with it by finding a spell to sure it, separating the diseased or burning them alive.  Each option offers its own challenges.

Balance

Physical attack types (Blunt/Cutting/Pierce) consolidated just to Attack

Removed Influence

Sovereigns all start with a party of Militia and a party of Spearman

XP formula is completely new to not be as influenced by combat rating.  Previously if you beat something that the game thought was tougher than you, then you would get exponentially more xp.  Now that rating modifies the amount of xp (you still get more if you are fighting tougher things), but not are severely.

Governor path changed to the Commander path (it has the prior upgrades for improving your empire as well as upgrades to improve your army)

Stinking Mud converted from a spell to a Crag Spawn ability

Arcane Veil is now a Defender ability

Aura of Grace moved from Air 1 to Air 2

Battle Cry is now a Commander ability

Broken Loyalties now costs gold instead of influence

Burning Hands now has an adjacent range (it can hit 3 adjacent units)

Moved Contagion to the Black Quire tech

Crushing Blow damage can be modified by traits

Most cooldowns moved to 5 turns instead of 3

Flame Wave moved to Fire 5

Moved Mantle of Oceans to Water 3

Switched Noble Legacy to boosting Dodge instead of Hit Points

Reduced the damage from Shadowbolt (the amount of resistance dropped is now based on the casters level instead of the damage)

When an Earth Elemental is summoned in battle he automatically shockwaves all surrounding enemies

When a Fire Elemental is summoned in battle it is surrounded by Inferno tiles

Familiars and Imps gain the Spirit trait

Flying now negates any move modifier from forests, jungles, etc

Counterattacks default to only doing 50% of the casters normal damage

Swordsman traits increase the amount of damage done when counterattacking

Companies reduced to a size of 6 instead of 7.

Adventurer sovereign history gives bonus fame from completing quests.

Tower of Dominion provides Fame and negates the City Count Penalty in the city it is built in.

Adventurers Guild provides 1 fame per season

Almshouse provides 1 fame per season

Amethyst Vault provides 2 crystal per season (instead of 1)

Archivist provides +50% research when the city is producing research

Embassy’s negate the City Count Penalty in the city they are built in

Guild Grocer improves hp by 5% (instead of 10%)

Infirmary gives trained units the endurance trait (instead of +1 growth)

Mining Guild provides +2 metal per season (instead of 1)

Pyre of Anniellum provides +2 fire instead of +1 fire and +3 mana and it unlocks at level 5 (instead of 4)

Tenfall University moved to unlock at level 4(instead of 5)

Reduced the unrest penalty from Slums to 5% (instead of 10%)

Tower of Dominion allows the city to ignore the unrest penalty from the amount of cities in your empire

Warehouse gives +50% gildar when producing wealth

Wood Shield moved from Training to Leatherworking

Spearmen are now trainable from the start of the game

Henchmen now use the best available equipment.

Henchmen cost Fame to train.

Increased the cost of quest maps

Reduced the amount of research given by the lost library form 20 to 15

There are more creatures in almost all of the goodie huts (larger battles are more common now).

Increased the cost per labor to rush from 1 to 1.5.

Berserker weapons berserk the units wielding them (making them uncontroalble in tactical combat and blocking spellcasting)

Added the “None” option to monster lair placement

Lowered the amount of monsters around the starting location.

Apiaries reduce Unrest in your empire.

Pastures improve the hit points of units in your empire.

Ancient temples improve Research for your empire.

Reduced epic tech pacing form x4 to x3.

Relias starts with the Discipline trait instead of the Veteran trait.

Most world achievements grant Fame.

You can't build Stables (and start collecting Horses) unless you have Mounted Warfare.

You can't build Kennels (and start collecting Wargs) unless you have Warg riding.

Sand Golems can use the Crushing Blow ability.

Shadow Wargs can use the Rush ability.

Removed the min turns required to raze cities.

Reduced the Mace, Spear and Battle Axe damage slightly.

Removed casting time from all summons except the largest (death demon and delin).

Moved the summon spells out of the spell ranks and into the Mage tech tree so casters that want to specialize as summoners can spend their trait upgrades doing that.  They will get access to lots of summons, but not to non-summon spells.

Reduced the Monk staff from 7 attack to 6.

Reduced the Crude Club from 6 attack to 5.

Reduced research from Conclave level 2 from 4 to 3.

Hundreds of other changes.

UI

New Battle results screen with animated xp bars that ding when you level up.  This screen also shows any injuries or effects from the battle so that we don't need additional popups.

When you have a unit selected and mouse over another tile it shows you the path the unit would take to that tile as well as how many turns it would take.

The Faction Power window now displays the attitude of that player to you.

Added an Army management screen when multiple armies are on one tile.

Switched the minimap and removed the unnecessary features from it (forests, mountains and chasms) so that the relevant info is more clear.

The Turn button will now glow yellow if the player can end the turn, but has idle cities.

New Bear model and medallion.

New Bear Cub model and Medallion.

Adjusted the stats that show up in the unit info window to more usable ones (set these to be controllable form xml in case modders would like to change the ones displayed).

New Mountains.  New texture, no more environmental creep onto mountains, no more mountaintop snow.

More defined terrain.  Less animation blending makes the terrain of individual tiles easier to see and less muddy.

New lighting with less bloom for more crisp varied colors instead of the washed effect in FE.

All units are larger on the strategic map, so they are easier to see.

Reduced the amount of ground props to make the map more clear and to make game impacting terrain features more recognizable.

New Rivers.  The banks have been removed, the flow speed has been halved and the surrounding vegetation and rocks have been dramatically reduced.

Removed the troop count from the spell selection window (In case you were wondering what those seemingly random numbers were at the bottom of the unit medallions).

New Leather armor designs for Tarth.

New Leather armor designs for Yithril.

Leather armor now supports cloth color (so they are all trimmed in the faction's cloth color).

Added dynamic shadows to units.

Fixed an issue where heavy black outlines would show up around grass and other textures with transparency.

The unit details wnd now plays the music theme of the owner of the subject unit, and doesn't change the music at all if accessed from a tactical battle.

The Kingdom victory screen now shows if some of the victory options are disabled in that game.

New ground decals for the goodie huts and lairs to distinguish them from the environment.