OtherSide Entertainment have, per the most recent Stygian Sentinel update, been making excellent progress on the playable prototype of Underworld Ascendant:

We’ve been extra busy the past 2 weeks working on the next iteration of the playable prototype. So apologies for not having much news to share.

Progress on the prototype is coming along nicely. The creature AI is now solid, with creatures being able to track you, maneuver across a range of challenging terrain, and close in and attack if they are so inclined. We’ve got a fun twist on the sort of stealthy AI we did with Thief, here where it is you being stalked by a stealthy predator.

We’ve been pushing Unity 5 hard, and extending the engine with some new capabilities to handle our particular needs for Underworld Ascendant. Together with the talents of our now half-dozen strong art team, we’re raising the visual bar for sure.

An initial round of voice acting has also been completed, and are doing some cool things with ambient audio, which you’ll hear in the playable. Along with this we’ve been refining the narrative elements.

Also, if you recall their last update, there was a fiery image that was the subject of a guessing game. That contest has been won; it turns out the image was of “a massive structure composed of flowing lava, formed and twisted into a tree-like shape by a powerful magic artifact, harnessed by the dwarves towards their arcane purposes.”

Which certainly sounds neat, it must be said.