I don't own a Xbox One, and Fortified from Clapfoot Games is making that a really difficult situation for me. Game Informer recently ran an article describing the co-op shooter:
"Fortified is a cooperative game that puts players in the shoes of one of four heroes, tasking them with defending a base from towering alien robots. Each of those characters has a play style that supports a different role in defense. While players can choose to play as any character at any time, a more diverse squad benefits from different perks. The Space Man can manage crowds, for example, but if someone sneaks past, the Rocket Scientist and her highly mobile jetpack are better for running them down. The different class-based abilities are a key part of how Clapfoot is making sure building tower defense elements like turrets and barricades isn’t the only thing that matters in Fortified."
Clapfoot Games co-founder Mark Ng even said in the article that the game use to have more of a horror feel to it, taking place on a ship in space where you had to defend against aliens. It's a great read, and the game is looking really cool.