I liked Xonanuts, but it has multiple issues. I wonder how many of these will be resolved in Xenonauts 2, but my hopes so far aint very high.
1. For one, the story was just plain terrible, as in basically non-existing. You start a campaign, and first thing you know you are to build a base. Unless you read what the game is about beforehand you wont even know you are to defend earth from aliens. There is no cutscene or anything to get you fired up, or establish the mood. For comparison UFO: AI did this very well with their short intro. And even after that the story is basically non-existent. One day an alien just pops up at your door surrendering. Ok, cool. So I will be able to interogate him and learn stuff right?... nope, turns out you can interogate him, but you are just a lowly soldier, no need to burden you with knowing anything, all you need to know is to point guns in alien direction, so the interogation result is not revealed to you... Plus the research texts (at least the ones in X-division) look like they were written by an edgy teenager...
2. Next is the weapon arsenal, there are what, like 5 different weapons and thats basically it for the whole game. Sure, you can upgrade to laser or plasma, but other than bigger numbers these mean nothing. For that I love UFO: AI, there each weapon has a role, feels unique, and they are all viable (except for the starting guns), and there is no such thing as a "laser shotgun"
3. Another issue is with the air combat, where losing aircraft is basically free, so you can simply spam hangars with cheap planes, and shoot each UFO the moment it appears even without really investing into air techs, which is a fundamental issue with the game design.
If xenonauts 2 were to improve on these while keeping the good parts of xenonauts 1 I would say it could be very good, but from what I have seen about the development so far it seems to me the devs are simply too unskilled to really know what they should be focusing on and are kind of doing random stuff that is even harmful to the game just to "justify" calling it a sequel...