I've been a fan of Doorways since Chapters 1&2 first launched. I found the first installment of the series disturbing in both atmosphere and story. I'm happy to say that Doorways: The Underworld is a superb follow-up in the series.
The developers have really progressed the story within The Underworld, although this time around instead of dealing with multiple serial killers, the game deals with just one and her many tortured subjects. Tortured subjects who will chase you throughout the variety of presented levels; such as caverns, sewers and even an abandoned hospital.
The atmosphere is even creepier and more haunting in this third chapter than it was in the first two chapters combined. The ambiant use of lighting along with striking, contrasting color schemes cause the vivid environment to really pop out at the player. The soundtrack, on the other hand, isn't much to write home about; it's mostly just soft sounds that lay under sound effects like foot steps and echoes.
The puzzles are key to progressing through the game, and up until the final puzzle they are rather easy. Go here, get this key, go back, unlock that door, get the next item you need, rinse and repeat. However, the final two mazes may present themselves as too challenging for some players. For myself, it took me a handful of attempts to finally get it down and it was fun the entire time.
My only big complaint with this title is the poor optimization. At some points, the game caps itself at 30 FPS, while at other points it will be anywhere from 60-80 FPS. It causes the FPS to drastically jump around throughout the game play. I played on the highest graphics settings, and eventually turned off special effects such as depth of field and it did not help the constantly fluctuating FPS. On my rig (specs in profile), this is completely unacceptable when games like GTAV run at a stable 60 FPS.
The Underworld lasts roughly 3 hours and has only a minimal replayability factor. So I suggest picking this title up on sale if you can. It's a welcome entry in the Doorways universe, and it will leave you on a cliffhanger, waiting desperately for Chapter 4 to come out of Early Access.