Door Kickers 2 was very briefly announced two weeks ago, but now there's more information beyond "it exists". The sequel to top-down breach-and-clear-'em-up is subtitled "Task Force North" and trades urban environments for a military Special Operations team fighting in a fictional "Iraqi-like" country. It'll be 3D, there'll be co-op, and it'll enter Early Access in September or October of this year. More details below.
From the Steam post, it sounds as if it's maintaining the core concept of directing small units of armed men through combat scenarios, with a reliance on sound tactics to stop you from being struck down. Much else sounds different, including having different kinds of squads to control, access to gadgets such as drones, and the ability to "take advantage of nighttime, darkness or even good old sneaking to surprise the enemy".
The structure around the game will change too, as it's now powered by their own 3D engine, will come with modding support including a mission editor, and will have cooperative multiplayer as well as the singleplayer missions and campaign of the original. Competitive multiplayer meanwhile "is still in the books but will make the subject of a separate announcement later this year". The development team also note that they're still very early in-development, so it's likely things will change and the early access release will lack many of these features at launch.
Stealth seems like the most natural extension of what the game included, and hints at the possibility of a more Commandos-like experience. If there are dinghies and the ability to dress up in your enemy's clothes, I'll be in heaven. And without that, it still sounds pretty good. Door Kickers was our best tactical game of 2014, after all.