I only recently heard about Xenonauts 2, when I saw demo gameplay in action on YouTube. After that I did some research and decided to give my honest thoughts on why I didn't like Xenonauts 1 all that much and why I am looking forward to Xenonauts 2. I bought Xenonauts 1 and it didn't quite "click" for me. The game itself wasn't bad, especially mechanically-wise and I really liked the strategical and finiancial aspects of it, so why I didn't like it?
1) No "passive" animations during tactical missions - It may look like a shallow reason for some to be thrown off by, but as YouTuber "Yeti" said: this made the game feel dead, and was a big reason for me, personally, why I had issues playing tactical missions. In Xenonauts 2 shadows do move and alive units seem to actually breathe, which is very important for making it look alive.
2) 2D made it problematic to navigate at times - Sometimes it was hard to move or see because isometric map didn't allow to rotate the map. Also, it was a pain to look through various "height levels". 3D solves this the problem of not being able to turn the map around, and there seem to be some other improvements already (such as your soldiers "glowing" green, which allows you to clearly see their position, even when they are obstructed).
3) Clunky field of view UI-wise - Xenonauts did a good job at showing you what you actually see (and making greyed out areas a possible danger zones). However, it didn't tell clearly enough who could see what in the UI itself. I am bringing this up, because it's very important when it comes to making choices when distributing "Areas of Responsibility". It'd be nice to highlight individual soldiers' field of view (like, in blue) by selecting a soldier.
I am going to watch how Xenonauts 2 continues to develop, because it seems to be displaying a commendable approach when addressing its mechanics and bringing in refreshing changes, so I do wish it luck.