Since I still haven't posted screenshots, I feel like I should clarify a bit on my comment about comparing it to a voxel world.
The game is definitely rendered in 2D with isometric tiles. There aren't any meshes or anything. Although, the game simulation is 3D tile/grid based. It is a discrete world, meaning game objects have a cell position and don't "live" in between cells.
In general the game simulation can be independent from the visualization. It's pretty common now to see fighters or platformers with 2D gameplay but 3D visuals. The Civilization series switched over to 3D rendering I think with Civ 4, but you wouldn't lose a whole lot if someone wrote a 2D renderer for Civ 5. In a similar way there is Mode 7 for SNES which allows you to render perspective, giving a 3D look. Games that use that could be on a 2D plane or in 3D, but my point is that simulation and visualization don't always have a hard link.
As a counter example, I worked on Toy Soldiers with 2 other programmers and the game would have to probably be rewritten from scratch to be rendered in 2D. I mostly say that because gameplay is entirely animation driven. It's to the point where there are "0 physics" in the game. If you watch this trailer
I don't think anyone could guess there isn't a physics simulation.
Anyways! I hope to post some screenshots soon and I think it'll be less confusing at that point. Some things are better understood in motion though, so I'll probably follow up with a video later.