Scenario: Brad gets hit by an alien armed with a stupid ray, and decides to hold a lottery- winner gets to design another game in the universe, using the same engine, with a reasonable budget and timeframe (one year to get game in a releasable state).  You win.

What do you guys do?

What I would do:

Try to make a new game, alternate universe as not to screw things up

Factions:  Kingdom Factions, Krax, a new human faction, and an unplayable AI superpowered Fallen faction.  (kinda like the idea behind At the Gates with the Romans- conquering Fallen cities can give tech, but they can curbstomp you early game easily).

Scenario: due to the influence, everyone forgot their knowledge of magic, and has to rebuild it, while conquering/allying with the other factions to make one kindgom strong enough to defeat the Empire. 

Research: would be used for spells, and traits, which would be faction-specific

Heroes: Each faction would have their own heroes, with unique trees.   3 times as many heroes as LH. (to ensure some variety)

Tech: most tech is buildable (like in the upcoming game), some tech gained through research/quests.

Wargs: food source for humans, mounts for Empire  Horses: food source for Empire, mounts for Kingdom  Warhorses (variety) would be quest (Capitar gets a bonus to mounts as one of their traits)

Shards: Empire has corruption, uses death shards for their magic.  Everyone uses uses Elemental/Life Shards.  Shards give research bonus for sphere-spells, half bonus for dual-sphere.

Crystal: no more crystal stuff for troops, crystal is used to buy artifacts for heroes.  Staves for troops are removed from the game.

Unit customization: armor sets would be unique by faction for leather/chain/plate/masterworked versions of each.  Hero bonus slots would be rings/amulet/ suits of armor (would include dresses and such) /weapon/accessories.  

Artisans: out in the world, find and place them in your city to gain a bonus in your city (sharp weapons, or Admin I/Merchant I/Loremaster I, other bonuses)