To begin with, Horizon is gorgeous. The game will be rendered in 2160p checkerboard (meaning, basically 4K) on the PlayStation 4 Pro, but its graphics shine even in 1080p on the standard PS4. This is the debut of Guerrilla Games' Decima engine, a new foundation for rendering video games with built-in tools for artificial intelligence, physics, logic and world-building. This is also the engine powering Hideo Kojima's mysterious Death Stranding, by the by.

Among the rolling vistas of lush wilderness, towering metallic beasts, day-night cycles and a dynamic weather system, one thing stands out as an accomplishment in Horizon: the characters' mouth movements. No matter how advanced game technology may be nowadays, developers still find it difficult to accurately animate the act of speaking. Mouth movements don't always line up with the spoken lines, or they're simply too stiff or repetitive.

Horizon's Decima engine doesn't solve this problem entirely, but it's the closest I've seen to realistic speaking motions in a video game. This one feature makes me happier than it should, and it's representative of the level of polish I experienced throughout my time with the game.

The introduction stars Rost, a burly man in furs and a Viking-style braided beard, as he hauls his charge, the baby Aloy, across a gorgeous valley and up a mountain for a sacred blessing. Rost explains the situation to Aloy as he walks, reminding her that they're both outcasts in the Nora tribe. He is not Aloy's father, and her mother's identity is a complete mystery, but Rost raises Aloy like his own, with warmth and respect in his eyes. It's a special, touching relationship right from the beginning.

The mystery of Aloy's mother is what truly drives the story forward, though. Motherhood is a central theme in Horizon, from Aloy's goal of discovering who her mother is and why her birth was seen as a curse to the hierarchy of the Nora tribe itself.

This is a matriarchal society, where women are honored for their ability to grow and nurture life. Women hold positions of power in their communities, and across the surrounding land, the villages carry names like "Mother's Heart" and "Mother's Cradle." The tribe's omnipotent god is called the All-Mother.

Before Aloy embarks on a quest to learn about her own mother, she's presented as a child desperate to be accepted by the Nora community. Members of the tribe are forbidden from speaking to her or Rost, a fate that makes her childhood lonely and frustrating. After an unfortunate encounter with some tribe members as a child, Aloy finds herself alone in a cave-like bunker filled with rats, corpses and the remnants of a long-dead, technologically reliant society.

She's not scared. Instead, she's curious -- she pokes around the cave until she finds a triangle-shaped piece of technology on the ear of a corpse, and she puts it on her own head. The world comes alive behind a translucent purple dome, and Aloy is able to investigate the various broken terminals scattered around the cave system. There are desks, bunk beds and many more corpses, some of which Aloy can tap into to hear their final voice messages.

This society might have been a cult; it might have been a group of people attempting to escape Armageddon. The cave is familiar -- these people carry names we would recognize, and they clearly come from a timeline very much like our own, but with significantly more advanced technology. Members of the Nora tribe speak of a people who perished because they didn't pay due respect to the All-Mother, and the cave is a testament to these tales.

As Aloy runs around the cave and the sprawling world above, the power of the Decima engine is on full display. Even just the way young Aloy runs, with a child's bouncing, uncontrolled gait, is completely endearing.

And then Aloy grows up.

From a young age, Aloy has a singular mission: Win the Proving, a test of hunting and warrior skill, and she'll be granted any wish she wants by the leaders of the Nora tribe. She plans to ask for the identity of her mother, of course. She trains with Rost, providing players with an opportunity to learn the game's controls in an environment that feels like a natural progression of the story.

Aloy's main weapon is a bow and a variety of arrows, including electric trip wires and firebombs, which she crafts with resources found in the wild. The triangle communicator device remains attached to her head, allowing her to receive information about new threats and creatures. That's right -- here's where those mechanical animals come into play.

Horizon's world is overrun with beastly robots: Horse-like creatures crafted out of metal and wires graze the grasses; artificial velociraptors prowl the prairie, waiting to pounce on intruders. Eventually, when Aloy leaves the valley to explore the outer lands, she encounters towering long-necked monsters roaming among the mountains. It's unclear where these metal creatures come from, but the tribes live with them in a tense kind of harmony. Tribe members hunt the smaller robots for parts but otherwise try to stay as far away from them as possible.

Using the triangle communicator device, Aloy is able to see the paths that certain robots take, allowing her to sneak around them in ways that other tribe members can't. Eventually, when Aloy leaves the confines of her valley, she learns how to tame the horse-like creatures and she's able to ride one from mission to mission.

Riding a robot horse feels really cool, in case there was any doubt.

Horizon offers players a variety of gameplay options. Lay traps to capture and kill as many metal animals as you can, or use stealth tactics to take down only the prey you need to. Bow and arrow, slingshot bombs, electrified tripwires, a spear -- the weapon choices and environments lend themselves to numerous different play styles.

I'm not patient enough for pure stealth, so I found myself leaping around the grasslands, diving away from attacks and laying into monstrous metal creatures with arrow after arrow. The trip wires are incredibly fun to use, but touchy -- if you attach one end of the wire to a rock but miss connecting the other end to something solid, that wire disappears from your inventory. It's safer to quietly lay down some traps and then initiate a fight with a metal beastie (not to mention, it's incredibly fun).

Horizon is huge. Even after nearly four hours of playtime, I only just scratched the surface of the world map, and I ran into at least six separate side quests. Horizon's world feels real and grounded; it's packed with intriguing characters from a range of backgrounds, all of which feel authentic to the game's universe.

Of course, Aloy is the most interesting character in the game -- which is certainly a good quality for a protagonist to have. She's a powerful, skilled hunter on a grave and mysterious quest that will undoubtedly reveal more than just her own personal history. There are so many questions in Horizon (Who is her mother? Why is she cursed? Where did the robots come from? Why did the previous society die off?), and Aloy is the conduit for all of the answers.

I've been dreaming of Horizon's world since finishing my playthrough, rolling these questions around and around in my head. But the main question on my mind has nothing to do with the game's lore. After playing the preview, I wonder: Will the full game be as gripping as the couple of hours I played?

Just like Aloy, I have hope.