Horizon Zero Dawn may well be the most pleasant surprise of E3

While perhaps overshadowed at Sony's E3 2015 press conference by showings from titles like Final Fantasy VII's remake, The Last Guardian, and Shenmue III, Guerilla Games' newly-announced big-budget action RPG, Horizon Zero Dawn, is a damn fine contender for the best major title at E3 this year.

Best-known for their work on the beautiful but plodding Killzone shooter franchise, Guerilla Games appears to be ambitiously merging an open-world with real-time action elements on top of major RPG mechanics, though Sony's press conference demonstration didn't give much of a glimpse on the RPG side of the game.

Welcome to Horizon Zero Dawn. It's quite pretty and some of the animals are robots.

In the closed-doors demo at E3, they go into a little more detail. Set over a thousand years after the collapse of civilization as we know it, gigantic robotic beasts wander the nature-reclaimed wilds of Earth - and it appears they may have had a little to do with humanity's fall. 

The Guerilla Games representatives giving the demo seemed keen to keep the mystery about this aspect of the narrative intact, though they did underline that the machines that roam the world are intrinsically connected to the story and the state of Horizon's world. 

The bow is Aloy's go-to weapon for most encounters, but it can be used in a variety of ways with different ammo types.

The idea of robotic beasts is novel and the design of those that I saw were all pleasing. Sheet metal plates and glowing lighting beneath the surface serve as a great showcase of Guerilla Games' technological expertise. I particularly liked the jerky not-quite-living animations of the mechanical creatures.

The post-apocalyptic world and the attire of female lead Aloy is a tad reminiscent of last generation's splendid Enslaved: Odyssey to the West. Horizon is obviously more technically accomplished and realized in a beautiful manner; it seems to display a level of artistry to its craft that felt all too rare at this year's E3. 

Running at a consistently smooth framerate, the technical performance was pleasantly stable in Horizon Zero Dawn's extended demo. It is truly one of the most visually impressive applications on the PS4 hardware that I've seen to date - the game is bloody beautiful.

Further clarifying the finer points beyond what was shown at Sony's press conference, I saw the same battle with the gigantic, dinosaur-like mechanical beast - but this time with a different approach. In the world of Horizon, Aloy is a particularly skilled machine hunter. Thus, in line with the game's allegedly seamless open world design, combat encounters can be approached in a variety of ways.

Given that the beast, called Thunderjaw, is much larger than Aloy, the element of surprise is of utter importance. A number of smaller beasts were in the vicinity that could be manipulated to turn the tide in Aloy's favor. These minor creatures behaved like cattle - they'll flee when startled, though some may also turn to fight if sufficiently aggravated - and crowd controlling groups of enemies like this is absolutely a viable option.

The world of Horizon Zero Dawn is intended to be a seamless open world with no load times and an open-ended approach to combat encounters.

Representatives of Guerilla Games explain that understanding how enemies operated in Horizon is absolutely key to acheving successful hunts. By learning how they'll react to certain things, the player can control them in order to divide groups, avoid attacks, or expose weak points. 

When the time came to do battle with Thunderjaw, the giant beast hurtled into a designated combat zone for this encounter, destroying parts of the terrain as it rushed forth. The developers were quick to note that there's a number of ways to take down Thunderjaw. In this instance, I saw them chip away pieces of its armor with Aloy's trusty bow and arrow in a manner that feels almost like a boss encounter from The Legend of Zelda. 

The bow appears to control like what you would expect from any third-person action game, but how it's used is the crucial factor that distinguishes it from other games. Aloy can fire multiple types of arrows, including explosive ones! I'm told that this will form the bread-and-butter of the game's yet-to-be-shown crafting system. Balancing which tools are right for the job and how much a player is willing to expend their arsenal on certain foes will be a constant priority.

Once Thunderjaw's weaker points were exposed, it was much easier to take down this enormous robotic enemy and the developers eventually put Thunderjaw to rest permanently.

Demonstrating combat from a stealthy lead-up to an aggressive face-off, Horizon Zero Dawn's extended gameplay demonstration came to a close. Even in the extended preview, we didn't see any RPG mechanics yet, though the developers again do point out that Aloy has a level and gains experience. Guerilla Games assured me that the game will mix deeper RPG mechanics with action combat. 

While the RPG side of the game remains a little of a mystery beyond some cryptic statements from its developers, Horizon Zero Dawn clearly has something special going on. Its combat looks exciting, while its world design and execution is beautiful - I can't wait to see more from it.

Horizon Zero Dawn is set to launch in 2016, and is available for pre-order now.