Mysteries abound in Valley's titular setting. Abandoned factories lie dormant between mountain crags, while far below, ethereal creatures flock to secluded hideaways. Much of the joy of Valley arises from its surreal environment, but also from the way you explore it: a mechanical exosuit propels you over grassy plains, through quiet caverns, and into the air over sloping hilltops as you investigate this forgotten corner of the Canadian Rockies.

There are elements of several games here: the movement and agility of Crackdown. The magical realism of BioShock. The subtle, lurking despair of Slender: The Arrival, the first-person horror game released in 2013.

The last comparison surpasses mere tone: Blue Isle Studios, the developer behind Slender, is also working on Valley. Judging by a recent demo, Valley is less overt with its horror elements than Slender. But the influences are clear. Blue Isle knows how to build atmosphere, suspense, and a mounting sense of dread, and as I glided through a small chunk of its world, Valley seemed to be stressing all three.

"We wanted to explore our own identity as a studio," designer Petar Markovich told GameSpot. "We wanted to touch on the same tenets that Slender did, but add in this locomotion, this exploration that expands the scope of our work."

The narrative will focus on the Pathfinder program, which outfits select people in L.E.A.F. (leap effortlessly through air functionality) exosuits. By exploring the mysterious valley where the game takes place, Pathfinders came across Amrita, a substance capable of renewing the life force of dead things. The game blends realism and surrealism with its blend of militaristic experiments and spiritual energy sources.

Amrita is also the fulcrum for one of Valley's most integral--and promising--mechanics. The L.E.A.F. suit not only grants superhuman agility and speed, but also the ability to manipulate life and death.

At any given moment, you can target a tree and sap its vitality, adding it to your personal Amrita supply. From there, you can use the substance to revive dead animals, unlock dormant passages, or, if the situation calls for it, give life to a different tree entirely. Markovich said this mechanic will figure prominently into puzzles in parts of the game.

But the life of the valley and your own are intertwined. Upon your death, the exosuit will utilize the energy from its surroundings to revive you on the spot, similar to the Vita chambers from the original Bioshock. There's a catch, though: If you sap too much of the environment's life, it will eventually drain, and you'll die for good. Or at least, you'll return to the beginning of the chapter.

"We want to tie the world to your character in a way that makes you consider your surroundings," Markovich said as he restored the life force to a few nearby trees, watching them sprout leaves and thicker branches from the interior of his L.E.A.F. suit. "That's a big part of the narrative, but also in how you move through Valley's environments."

That manipulation of the world's life source factors into the combat as well. You'll encounter wraith-like enemies along the way, brimming with dark energy in the recesses of dormant military facilities. There's a tense quiet to my recent demo, but it was punctuated by sudden encounters with these phantoms, as they hurled orbs of harmful magic in the protagonist's direction. By stockpiling Amrita before these fights--but not so much that I couldn't respawn immediately--these fights were much easier.

And that's why Valley piques my curiosity: the idea that the world around me is malleable, and that my actions could have consequences in the long run. From what I played, and from what Markovich showed me, it's unclear whether that thread will remain throughout the entire experience when the game releases later this summer. But as of now, Valley's fluid traversal system, intriguing life-and-death mechanics, and subtle, mysterious world show promise.