Deus Ex Mankind Divided Key

Mainly due to the fact that all the games in this series, including Deus Ex: Mankind Divided, give you a huge freedom of choice. It's not just an FPS game, it's a stealth game and an action role-playing game.
It's up to you whether you're going to go through each area with a gun in your hand, sneak quietly behind enemy lines, or simply talk to make room.
It is one of the most complex video games of its time.
It's your decision what you're going to do. This freedom is the main reason why the series has become so popular among players.