I somehow managed to play for 15 hours or so since Friday, so I think I've got most of the mechanics of how the game works.
Really enjoying it so far. It's a similar experience to XCOM 2 with the same janky graphics engine (XCOM 3 really needs to use Unreal Engine 4) but is different enough to not feel like a reskin of that game.
All the XCOM soldier abilities are fairly different to the last game. Godmother is probably close to a Ranger class, Terminal (healer) is a bit like a support etc. I haven't unlocked a sniper yet, not even sure there is one in the game as it's mostly close quarter combat. There's an excellent melee alien who I have been relying on to run around doing major damage and then parrying shots afterwards (with a cool effect)
Although soldiers don't die, they can be knocked down during a mission and you then have to stabilise them. How it is different to the previous games is that your soldiers don't have any recovery time between missions, even if they are gravely wounded. They do end up with 'scars' which give them some serious debuffs though. My medics mobility was hobbled, so evacuating from missions where there are infinite enemy re-inforcements became more difficult.
You can put them in tactical training to lose the scar debuffs but then they aren't available for 2-3 'days' which could mean 2-3 missions, so the game is encouraging you to not rely heavily one one particular squad and to vary your playstyle more.
There doesn't seem to be much importance placed on movement/positioning now though. I mentioned most missions I've played are inside and don't have a lot of high vantage points to take advantage of. Most missions consist of 'Breach', clear a room as quickly as possible and then breach again, usually twice or three times. Sometimes you have to extract at the end with a VIP, sometimes you have open a chest but most of the time it's just 'kill everything'
I'm playing on 'Expert' difficulty and I'd say that even feels a bit too easy, so I might do another run on Impossible once I've completed it, but the fact I can see myself playing it again is a good sign.
If the three factions you investigate I've completed one and am probably 80% through the second one. Not that you really play these for the story.
Anyone needed to use a backup android? I have had one since the early mission but literally not needed to call it in.