Watch the “Marvel Strike Force” announcement video: 21st Century Fox’s FoxNext Games and Marvel Entertainment have doled out new images, gameplay video and other details for “Marvel Strike Force,” a new squad-based role-playing mobile game set in the Marvel Universe. Set to debut in 2018, “Marvel Strike Force” players recruit five-member teams of Marvel’s superheroes and super-villains to battle in what the game’s developers promise will offer an unprecedented level of interaction between characters. Players will join forces with S.H.I.E.L.D. director Nick Fury as they assemble their fighting squads, picking among characters including Iron Man, Captain America, Black Widow, Spider-Man, Venom, Star-Lord, Gamora, Daredevil, Groot, the Hulk, Thor and Doctor Strange. In the multiplayer game, players create alliances and collect new gear and upgrades to make their teams stronger — with the goal of defeating their foes in strategic combat. “We talk about the game in terms of fantasy...