I have the game.
I hate it.
While most of the game is a copy of good old UFO from 1994, the tactical maps are no longer random. Which may just seem like a little issue, but it ruins everything: In any mission the player is guessing what the level designer did, no longer looking for aliens which can be anywhere. And the aliens really are where you'd expect them.
Then there is the point that the number of maps is limited, any you can expect to run across the same maps a few times. When you just know what to expect from where.
Anyway, the maps give a "level" feeling: Built for the tactical challenge (such as it is), but the "people are living there" vibe is completely lacking.
Linked to this there is the difference between progression and mission: In UFO 1994 it feels like the UFOs are doing missions: In a given area, first some scouts are active, and then the heavies follow. In Xenonauts the small scouts are no longer sent once the big ships arrive. Which follows the logic of game progression, but kills any kind of immersion.
Oh, and of course the squad size has been reduced as well. I really loved to send full 26 guys into a battle, even if this was way more than necessary. But having too many guys would ruin the handcrafted maps of Xenonauts, or whatever.
With UFO 1994 I invaded Cydonia several times. In Xenonauts I the weaknesses offended me so much I could not keep playing past mid-game.
Do not buy it. Sadly, it is no more than a pale shadow of what might be - or what was reality in 1994.