Apparently, Nights of Azure is a "darker direction" for Gust, thanks in part to the game's director being best known for Fatal Frame and Deception IV. So you can probably assume that it's not all butterflies and rainbows.
Take a look at the first media and the official announcement too.
Nights of Azure Announcement Trailer:
Nights of Azure screens:
KOEI TECMO America is delighted to announce the upcoming western release of successful new IP from GUST studios, Nights of Azure. Originally released in Japan this fall as Yoru No Nai Kuni, Nights of Azure is currently development for the PlayStation 4 computer entertainment system, and is slated for release across North America on March 29th, 2016. In celebration of this announcement, KOEI TECMO has released a new, introductory trailer for this new IP, along with a first batch of assets.
Under the direction of Keisuke Kikuchi (Fatal Frame, Deception IV), Nights of Azure marks a new, darker direction for GUST studios while maintaining many of the gameplay elements adored by dedicated fans of the studio.
Nights of Azure is a tragic tale of two friends faced with impossible decisions that will test their loyalty to their quest and to each other. Set on an uncharted island that floats in the North Sea, Nights of Azure paints a picture of a land where nights are tormented by azure-blooded demons. In this kingdom of Ruswal, very few people leave their homes after the sun has set, let alone have the strength and skill to take on these powerful monsters. One of the best among these brave few is the protagonist, Arnice, a knight of great skill and power, who is assisted by her friend and priestess Lilysse in a quest to rid the land of demons. However, they soon find out that the solution to the island’s problems might not be as simple as defeating enemies in battle.