It's a mishmash of modes and ideas from both their previous titles and other games out there. It just looks really refined and has something interesting for most people. It also eschews the Call of Duty crowd pleaser game mechanics for the most part. A big focus on objective completion, teamwork while still retaining fun FPS elements. Game looks awesome, watch some videos sometime.
Playing: Dark Souls 2: Scholars of the First Sin Watching: Mr. Robot