What are the biggest changes that one would notice in Etherlords II in comparison with its predecessor (Etherlords I)?

The single biggest change is the new focus on adventure and RPG-style gameplay as opposed to the turn-based strategy play that was central to the first game. This new approach was something that we wanted to do even before finishing the original game, and as luck would have it, the majority of Etherlords fans also wanted it. This very radical change allowed us to rethink how you play the game and led us to implement a whole range of changes that include a much deeper and involved story, a single hero that evolves and gains experience throughout each campaign, NPC characters, side quests, new modes of travel like tunnels and teleporters, as well as sailing ships and new structures that will affect combat within a certain radius.