No one heard its approach, but Door Kickers forced entry to Steam and took it by storm. Ian described it as a perfectly pure, focused strategy game in which each stage was a puzzle to attempt, fail and try again. He wasn't so keen on the militarised police, but Door Kickers 2 solves that one: you are the military, and the baddies are non-specific Middle Eastern terrorists, so I doubt you'll need to concern yourself with taking prisoners.
Door Kickers 2 is aiming to hit Early Access in the last few months of this year, which seems a long time, but the feature set makes the original look small and unfinished by comparison. The top-down maps are in 3D, for one thing, windows can be smashed, ledges can be vaulted and assaults can be attempted under cover of darkness. Drone strikes are one of the many morally suspect options available to you in dealing with new threats such as suicide bombers and IEDs.
Subtle it is not, but viewed as puzzle elements they're complex, varied and changeable. On paper at least they advance Door Kickers' strategising to a degree worthy of a sequel and not a map pack (and the mod support will take care of that point).