I think the spider swarms were in the original books as well. They're terrible design at low levels in the tabletop, since they basically require a dedicated AoE caster or a pile of alchemical weapons to deal with. Owlcat even reworked that spider cave several times and had Bokken give you some alchemical fires to make it easier.
If they follow the Wrath of the Righteous books closely, the
Vescavor Swarms are going to be a nightmare. Just about every campaign has at least one curveball that can wipe the party if you aren't prepared, and every time I've played through Wrath, the party had a hell of a time with these guys. They aren't optional either, unlike some of the more egregious encounters in Kingmaker.
Haven't been keeping up with the Kickstarter updates, but since it's over in a few days, here's a quick update. The current goal is for an optional tactical battle system for army combat, said to be similar to Heroes of Might and Magic 3. It sounds pretty lofty if it isn't a simple minigame, even with some former HoMM devs on the team.
The goals that have been met since my last post are the
Oread race, two extra romance options, more combat animations, and more racial features. These features include one race-specific archetype for each race, more race-specific feats, and alternate racial abilities to choose at character creation. Two known archetypes are the Dwarven
Stonelord Paladin and the Elven
Spell Dancer Magus.
The Oracle's confirmed Mysteries are
Ancestors and
Battle. No confirmed archetypes or Curses, though the curses referenced sound like Lame, Hellbound, and Powerless.
The Shaman's Spirits will include
Battle,
Bones, and
Wind, and their archetypes will include
Spirit Warden,
Unsworn Shaman, and
Witch Doctor. There will also be a new archetype just for the game called the Spirit Hunter, which gains some Magus-like abilities.
Other custom archetypes include the Arcane Enforcer Slayer, which gains Arcanist Exploits, and the Stigmatized Witch, which is a Charisma-based Witch with an Oracle's Curse. The custom archetypes have supposedly been worked on with Paizo authors, to keep them in balance with the existing archetypes.
Looks like the tactical battle goal is about to be met, and the guess for the next one is more global map events.