Previous Metro games have more or less been linear, allowing little room for deviation - but with many games going open-world nowadays, the question remained whether Metro Exodus would follow suit:
"We're not entirely open-world, then, it's more sandbox survival and everything is tied together with an overarching storyline that still carries the player through. They'll still feel like they're playing a Metro game."
Whether main and side quests will play a part, like in traditional open worlds, is still unclear - but Metro Exodus will still have some of the old-style gameplay, according to 4A:
"It's a combination of the classic Metro gameplay that everyone is used to from previous games where it's that linear style of gameplay. The level that we show in the trailer is later in the game and is one of our non-linear levels"..."There's a lot more exploration, there's a lot more open freedom in the sandbox areas to explore, to go in the direction you want, to do the things that you want. There's still story within those levels that will guide you through the places you should go but it supports being able to go where you want and do what you want."
Metro Exodus continues the story of Artyom from previous games, and will launch for PS4, Xbox One and PC sometime 2018.