XCOM 2

Firaxis's 2016 sequel starts from the assumption that you lost the first game. The aliens won, they run Earth as a benevolent-looking regime, and XCOM is a guerrilla force operating out of a stolen alien ship - which flips the tactical framing entirely. You now begin most missions concealed and get one free ambush, most maps carry a turn limit, and the enemy gets reinforcements, so the previous game's careful overwatch-creep is actively punished. Maps are procedurally assembled rather than hand-built, so memorising layouts stops working. Soldier classes are broader, the Ranger's sword and the Specialist's hacking drone give squads more angles, and the strategy layer is a real-time race across a world map against an Avatar Project timer that will simply end your campaign. War of the Chosen, the expansion, adds three named nemesis enemies who hunt you across the campaign, three resistance factions and a strong new set of classes. It is significantly harder than Enemy Unknown and better designed for it.