Killzone developer Guerrilla Games' PlayStation 4 RPG Horizon: Zero Dawn was one of the standout titles of E3 2016 last week. It's a hugely different game than the developer's well-known Killzone FPS franchise, and, based on a demo we played at E3, it's one to watch.

GameSpot caught up with director Mathijs de Jonge to discuss the game's recently announced delay to 2017 and why it chose a female protagonist.

Regarding the delay (Zero Dawn was previously expected to launch in 2016), de Jonge said Guerrilla Games is spending the extra months of development polishing things like quests and the robot-dinosaur Machine creatures.

"It's all polish," he said. "We have this open world. It's very big. We have a lot of quests; we have a lot of different regions as well. We have a lot of different Machines. Just playtesting this, it's very, very time-consuming. We have so many components. We just want to raise the quality on the different areas."

The director specifically mentioned some story and dialogue sequences, as well as facial animations, as areas that Guerrilla is looking to further improve before launch.

He added that Zero Dawn is currently in a pre-alpha state, which gives the developer enough time to "raise the quality."

"[The delay was] mainly because it's such a big game," de Jonge said. "We are a team of 200 people now, but there's just a lot of content we need to look at and evaluate and keep improving."

Zero Dawn was announced at E3 2015, at which time it was also confirmed that the main character would be a woman named Aloy. De Jonge told GameSpot that one of Guerrilla's goals from the start was to make Zero Dawn a game that stood out from what the studio had made before and what the industry has seen.

"When we started with a concept we felt like we had a pretty fresh mix of ingredients; the BBC nature documentary kind of feel, and then the sci-fi elements with the robots," he explained. "We also felt like we need a fresh main character. We've been making Killzone games; we've done male protagonists for quite a while. Now, we wanted to do something else.

"We're switching from first-person shooter to open-world action RPG. Everything is shifting, so this was another thing we wanted to try. And we felt like a female character like Aloy would fit in really well."

Looking beyond Aloy's gender, de Jonge said it was important to make Aloy an interesting character that fits within the Zero Dawn universe and draws players in with her inquisitiveness.

"What we have been focusing on is not if it's male or female, but it's more to figure out her personality," he explained. "Make her personality really interesting. And also the way she looks; make that feel like she's really a tribal hunter. That fits in this world and surroundings.

"She's very curious and determined, and she wants to explore the world and figure out these mysteries," he added. "And hopefully we can give the player the same feeling; you want to know what's out there, you want to discover these new Machines, you want to meet the new tribes. That's how we've mostly designed her character."

Last summer, PlayStation Worldwide Studios president Shuhei Yoshida said Sony thought it might be "risky" to have Zero Dawn's lead character be a woman. There was so much discussion inside of Sony about Zero Dawn having a female lead that the company hired a marketing team to conduct focus testing for the character.

Following the delay, Zero Dawn is now scheduled to come out on February 28, 2017 for PS4. For more, check out GameSpot's preview from E3, "Horizon Zero Dawn and the Thrill of the Hunt."