This game is pretty much exactly what you would imagine a 400K-word game about being a masked plague doctor would be like.
It's a fairly grim tale. You are a travelling doctor forced by the crown to enter a city in quarantine due to the Waking Death, a plague which makes its bearers sleep-deprived until they die.
You work with two others, a man wearing a boar mask and a woman wearing a fox mask. The town is surrounded by starving soldiers who want to sack it, is run by a despot mayor, and has at least two insurgent groups inside and multiple religious sects.
Although many exciting things happen in this game, the writing is slow-paced and dense. Here is a description of stars, for instance:
"The stonework of the courtyard fountain feels cold and uncomfortable against your back, as you gaze up at the sky. A persistent wind, the same one that caused you to bundle up your robes and seek shelter behind the stone structure, has left cracks in the relentless march of clouds, allowing occasional points of light to blink through. You ignore the creeping ache as the winter night assails your bones, focusing instead on those distant glimmers. Are they miniature suns? The faraway eyes of watching deities? Or simply another act of nature, like the snow, or the rain?"
I enjoy this style of writing. Given the large wordcount of the game and the dense prose, it took me several evenings to finish this game. And it branches quite a bit. My playthrough went against the grain, so to speak, as I supported the despot mayor at every opportunity and sought after (and found, to my detriment) the forbidden knowledge at the heart of the town.
Despite my 'losing' ending, it was written very well, with a lengthy epilogue that made the game very satisfying. It's always a huge bummer to get to the very end of a choicescript game only to have an abrupt 'you lost' ending, so having this 'you lost and here's what happened to the shattered wreck of your mind and body, and all those you loved' is definitely refreshing.
Also, I found it fun to roleplay as SCP-049 in this game.
Comparing this to Heart of the House, another long, slow-burn horror game, I'd say that Mask of the Plague Doctor is more like The Haunting of Hill House or The Turn of the Screw (more philosophical with more implied/ambiguous horror) and that The Heart of the House is more like a Stephen King novel or Dracula (events that are clearly supernatural and terrifying). Fans of both games may also like Blood Money, which has you playing a more cutthroat character.
I received a review copy of this game.