A Brief History:
As a side note, here are some purported screenshots from the game:
- After shipping Syndicate, Starbreeze decided that making internal engines was a bad idea, and moved to Unreal Engine 3 for Brothers: A Tale of Two Sons.
- Around this time, Starbreeze also bought Overkill, a studio made up of GRIN (Bionic Commando, Wanted) veterans, who had made PayDay: The Heist. PayDay was made on GRIN's Diesel engine, which they somehow kept after GRIN's bankruptcy.
- PayDay 2 launched to great success, and generated more profit for Starbreeze than they had in all of their previous ~14 years combined. As such, Overkill's CEO got promoted to run the entire company.
- Overkill's CEO decided all the company's games should run on GRIN's Diesel engine, because he was convinced it was amazing and magnificent.
- Starbreeze realized that the Diesel engine was actually a huge hindrance to them on all of their new projects, including The Walking Dead, and in September 2015, bought a company that made the "Valhalla Engine" for $8.6 million. They subsequently moved all their in development games to this engine.
- Today, Starbreeze announced they're moving off the Valhalla Engine and onto Unreal Engine 4. However, they assure everyone that buying the Valhalla Engine was a great business decision, and that the entire engine shall now be a plugin for Unreal Engine 4. Of course, only Starbreeze and their close associates are able to use this engine, so we're unlikely to learn more about this amazing technical feat.
- Starbreeze has stated that this move has not impacted the release date of The Walking Dead.
- In other news, Starbreeze announced that The Walking Dead was delayed to Fall 2018 a few months ago, from its original release date of Fall 2017, which was a delay from the game's original 2016 release date.
As a side note, here are some purported screenshots from the game: