As you can probably guess from the title Xenonauts 2 is an upcoming turn-based strategy game heavily inspired by the old XCOM series. What this means in gameplay terms is that you will have persistent soldiers that become stronger from mission to mission, fully-destructible environments that allow you to create your own cover, a variety of research and equipment options, as well as the same style of turn-based combat the XCOM series is by now famous for.
Xenonauts 2 is currently under heavy development, but if you would like to get a sneak peek and also help the developers out by giving some much needed feedback, you can do so by heading over to GOG. Just keep in mind that this is a pre-alpha demo we're talking about, so bugs and missing features are to be expected!
If you encounter any problems, or if you have any ideas you would like to share with the developers, make sure to stop by the official forums. And as a final note, here's a couple of images showcasing Xenonauts 2's current state: