I'm surprised Orgahs aren't talking about this yet. Been playing since a week and already finished it once and started a second play-through.

It's basically consists of running around a large map ala TW games, and the battles are fought on small hex based maps with individual soldiers. Simple concept but a lot of fun. Furthermore on the world map one can run into various random encounters which can lead to dialogue or battles.

The units have five major classes (although native units and European units have different classes the concept is same), soldiers, scouts, hunters, doctors and scholars. The corresponding native classes are champions, warriors, trappers and shamans.

The storyline has a lot of choices and good scope for roleplaying. Some choices affect the story, others merely affect the morale of your units (based on their individual characteristics). Morale in turn decides their effectiveness in battle. All in all the story is decent and the ending choices are really fun.

Spoiler Alert, click show to read: 
In the conquistador ending you can actually emulate Hernando Cortez's decision and completely subjugate Mexico

Very fun game. The only downside as yet is that there are some bugs, but the devs are quite active and responsive and updates are around the corner. And there's a in-story follower that only Kickstarter backers get but that too might be changed in the future.
All in all, fun game and I recommend it.