The developers behind Grave have set out a clear feature and gameplay list; this list is included below from their Kickstarter.
Day and Night
Because Grave has a day and night progression, the game takes on a different feel for each time of day. During daytime, Grave is primarily an exploration and fortification experience.
Players can explore new regions that have cropped up during the night, gather resources and prepare for the dangers that await them in the darkness. The emotions connected to the rise and fall of the sun each day are crucial to the experience of Grave.
Grave is a game about choice and divergence. Almost every item, creature or location in Grave has at least two ways of interacting with it, to suit the gamer's play-style and desired experience.
Those who are interested in tense action can arm themselves with defensive weapons and trek out into the night. The more cautious player might fortify themselves in a safe place and attempt to wait out the night. Some may like exploring the many strange landscapes of Grave, while others will be very goal oriented and only stop when their supplies run short. It is important for the experience of Grave to be dynamic and fluctuating, so that the game presents unique opportunities at ever turn.
In Grave, the goal is to do everything we can to keep the player reactive and the experience fresh. If you think waiting out the night is always the best idea, you run the risk of not finding useful items that appear in the fleeting locations that exist each day. Every enemy and situation requires new reactions, and we are using procedural/random systems to keep the experience exciting.