Bruce Straley, director of Naughty Dog's Uncharted series and The Last of Us, has explained why he decided to take a break from game development, which later turned into his departure from the studio after 17 years.

The industry veteran decided to take a break after the release of Uncharted 4: A Thief's End in 2016. Straley directed the project with Neil Druckmann following their work on immensely successful survival tale The Last of Us and Uncharted lead Amy Hennig's high-profile departure.

In an interview on Kotaku's Splitscreen podcast, Straley described Uncharted 4's development as "the hardest project" he had worked on.

"Uncharted 4 showed up and it was like – I guess there's a difference between doing something for yourself which feels passionate – and I had my own theories that I was trying to expand upon between Uncharted 1, 2, and The Last of Us – and then Uncharted 4 became more like, 'How do I do this for the team and for the company?'

"We needed to get the game out the door, and we needed it to be something good, so that it didn't put a mark on the Naughty Dog name. I felt like, I guess in hindsight I took on that role more for the team than for me personally.

"Also, we did that game in two years, from the moment that Neil [Druckmann] and I stepped on, almost to the day. Two years to create that beast, that then became the hardest project [I had worked on].

His break, Straley says, "had nothing to do with Naughty Dog, nothing to do with games". He says that after years of triple-A game development he thought to himself: "'Oh my god, it's time to take a break. It's just time to step away.'"

He worked on a deal before taking the reins of Uncharted 4, admitting he needed time off.

"To their [Uncharted's co-presidents] credit, they appreciated what I was willing to do and what it was going to take to get it done, and without batting a lash they said 'Sure.' So utmost respect to them as leaders and people who saw what needed to happen, and respecting my time and my energy, and giving me the time off.

"Just to jump forward, having that time off, it just kind of eked into... What was a few months became more months, you know."

Straley's break turned into a permanent departure from Naughty Dog in September 2017, and he described it as the "hardest decision" of his career.

"As I close this chapter with a heavy heart and an appreciation for everything Naughty Dog has done for me, I open the next with an excitement to continue the journey into the creative process," he wrote. "I don't have anything to announce just yet, but I look forward to the discovery and to sharing it with you all soon."

Straley hasn't yet revealed what's next for him.