Played almost an hour (enough to go through the tutorial missions) so I have a bit better idea how the combat works, and I know this is a game I will enjoy.
Basically you get a set of cards, a meter indicating how many cards you can play (default is 3 right now, but you can play other cards that may increase that for the next turn) and cards will build up Heroic points which can be used for non-card attacks or special cards that require Heroic points to use. Cards are character specific, but you have just one hand of cards (as opposed to choosing a character and having separate hands of cards), so in that way it's not like XCOM at all. You CAN move one character once per turn to setup attacks, which is XCOM-like and the non-card attacks are also like XCOM, but I would say this is more Slay the Spire or Darkest Dungeon than it is XCOM.
Cards work like normal card games: You use an attack or a skill and it does the thing. Unlike XCOM games, there is no "to hit" chance. So if you're complaining about RNG with the cards, at least you won't have to worry about RNG in the attacks. If a card says it does 5 damage, it will do 5 damage. It won't miss (and so far it also won't crit). The strategy comes from what cards you play in what order, where you line up your Heroes and how you use effects to take out as many baddies as possible (e.g., using a knockback to hit two minions together to take them both out, etc.).
Again I've only played the tutorial, so I could be wrong on this, but the combat has been in small combat "arenas" with waves of enemies. I'm not sure if there will be open maps later XCOM style or not, but that's what I've seen so far. There is no cover system, but some Heroes have block abilities that they can use on themselves or others (it's a card use similar to adding Block in Slay the Spire, but it doesn't disspate after each turn).
That's about it for now I think. I haven't really started the chatting aspect, but I'm liking the comic vibe and the chatter is good (decent voice acting). Graphics are good, though there didn't seem to be any shader cache beforehand, so every attack stuttered the first time and was fine subsequent times. I'm running 1440p 21:9 Epic scale with all Ray Tracing and I'm on an AMD card (6950) so it isn't pushing the rays too hard. No DLSS or FSR that I could see in menus (possible it has DLSS but didn't show up for me since I don't have nVidia).
I can report back later, or you can ask questions if you have. But pretty pleased with this for me - won't be refunding.