Jagged Alliance 3. I just love this series and this is really a great return to the old classics of JA2 and JA after a shitload of failed attempts to reboot the series in recent years/decades. It's far from a perfect game, but if you liked the original JA-games you'll like this one. If you think it's like Xcom or other more modern turn based strategy combat games you might be disappointed.
This guy makes the point perfectly in this video:
https://www.youtube.com/v/GddMTHg4yycThe JA-series is much less about "the numbers" in my view. Of course stuff like the weapon you use, cover, the stance your merc is in, his stats, range, visibility and other things play a big part, but the focus is more on strategy and how you're positioning your team members. By not giving you the "95 percent hit chance" the game is much less frustrating and it just kind of forces you to make decisions based on what seems reasonable. A lot of the criticism I'm reading on Steam seems to be based on those wrong expectations of it being another Xcom or a modern turn-based strategy game. If you know the original series, I don't think you'll have any issues getting into the new one, because it plays very much the same, but has also added some new features (like overwatch) that fit very well.
Overall (not only looking at the actual combat) I think they've done a great job of capturing the old JA-spirit. I like the big map overview with all those places you can got to. Great interactions so far with some of the NPCs and more quests it seems. Quests were great in JA2, but I would have loved it, if there were even more side-quests you could do. It seems in JA3 they've addressed that issue.
However, there are some things I don't really like that much. The UI (outside combat) is just a complete mess. Not sure, whether they'll give that an overhaul at one point, but one thing they really have to fix is the inventory management which is a horror show at the moment. It feels like it was done for a console game even though the game isn't even released on console. You have to manage your weapons, various ammo types and multiple squads and stashes and it's an absolute clusterfuck. You can't sort things, you can't transfer items from one squad to another without multiple clicks and switching between them and the screen they make you use to do all that only you shows you a fraction of the things you need without scrolling or clicking/switching between characters/squads. They really need to fix that (or if they don't hopefully a modder will do it).
From the looks of it, they seem to encourage modding of the game. There's a Steam workshop from day one and Haemimont themselves have put things there already (like a mod that gives you hit-percentages). JA2 had loads of mods and the biggest one is still going to this day and is still getting updates I think. So, the community seem to be willing to put in some work themselves to improve the gameplay experience or add new things. I hope the base game is a good starting point for that and that loads of JA2-players make the switch and like the new one.
The only other thing I don't really like so far (except from the UI) is that they left out Bobby Ray's from JA2. All the stuff you do in the game (apart from the actual combat and sector exploring) is done on a laptop and you have some websites you can look at. A lot of them (in JA2) were just flavour/lore stuff and were there for laughs, but you also hire your mercs on the "internet" and Bobby Ray's was a weapons-shop where you could order stuff that would then be delivered (after a few days) to the airport. The interet is still there in JA3 and you still hire your Mercs there. They also seem to have some of those "flavour"-websites that are there just for fun, but there's nothing to order weapons or other stuff, which is a disappointment. Hopefully that can be added in the future with DLC, mods or even a sequel.
All in all, I'm really, really chuffed with this new JA-game...