It's basically still CC: Invasion Normandy. Some changes to the Campaign map and layout were implemented. AI was likely changed, but nothing game-changing from the original.

If you're familiar with the original, then the mechanics will largely be the same. The grand campaign itself (that I've played so far) has been changed up a bit. Thus far it looks like you don't have to go all the way across Normandy itself (which tbh, was usually pretty devoid of enemy units in the original anyway), though if I do one of the other campaigns and there's different sections to the original's whole northwestern part of the OG map, I'll be sure to update this. I'm not going to complain though, as the changeup isn't bad. Seems like there's a number of more beaches to hit, and appears themed more towards what happened the first few days of Overlord.

Instead of the landings being clustered into the same first turn, you start with the airborne units only and at "night", which is the brightness turned down a bit. Whether or not this has any significant impact on spotting, I can't quite tell yet. The grand campaign in general focuses more along the coast. That's great, because only being able to really hit Utah beach for all those years was already getting old 20 years ago.

Just like the original, the Germans are notably under-powered. Some might complain about that, but it presents its own challenge when you play as them, which I don't mind. If you've been playing the series since the 90s, you're still probably going to want to change the difficulty sliders to elite for whatever side you're playing, and then to recruit for your opponent.

The AI still seems mostly the same. I haven't been able to tell too much of a difference, although they don't seem to go on the suicide charges that they used to with running their mortarmen up on the front lines, so that's a plus. That said, I feel more like I have to hunt the enemy down a bit more than before and that they'll have more ambushes setup. Whether that's intentional or just random placement chance, I can't quite tell yet. (I'm about 6 or 8 battles in.)

One thing they DIDN'T do though was scale or otherwise update the UI on the campaign map, starting screen, or battle results. It's still going to look like a blown-up 640 resolution, which is mildly annoying. Still though, I love being able to see damn near the full map on at 2K. I probably wouldn't set it to 4K if you have anything less than a 32" monitor, as the unit info and sprites during battle are still going to be scaled for the original, making it wildly difficult to see them even with a 32" monitor. 2K seems to be the sweet spot for me. You might want to bring it down to 1080 if you're using a 24" monitor.

The audio has stayed largely the same. All of the original voiced lines are there, but I've noticed a few new ones thrown in as well; however those seem to be at a minimal. You'll notice it more with the lines in German, but there's some English ones as well. One BIG plus on that front is that they also put in lines voiced in Czech for the Osttruppen, which I'm appreciative of.

There's been some changeups in the unit configurations. Some are just name changes like making the old BAR squads into MG Squads, but others are in unit counts for the squads as well as differences in loadouts. I'm finding my guys run out of ammo more quickly than in CCV, but fortunately the scavenging mechanic seems alive and well, so you can always get some more guns from enemy casualties - or at least try to coax them to by moving your guys over them. One QoL feature that would have been nice to add is something telling your guys to specifically scavenge when low on ammo. As it stands, such things are still at each units discretion. (You can lead a horse to water, but...)

There's a few other QoL things I could think of pertaining to unit information displays and the like that could use some updating. Rearranging how each squad is laid out on the actual battle screen. Group each platoon together with a space in between to try to keep some unit cohesion and general tracking of each platoon's condition, rather than just sticking with three rows and squads listed sequentially is something I'd be in favor of. Another would be more nuanced information in a better UI. In the settings, you can only pick the one general element to track using the background color of each squad. Having more of those elements in something that can be quickly identified in the company view at the bottom of the screen would be much more helpful and useful, without having to either hover over or click on the individual squads. Better situational awareness is generally much more advantageous. A serious overhaul of the AI would be a welcome change as well; have the difficulty sliders actually alter behavior in a more significant way rather than just altering the condition of your supply status and number of troops at your disposal. (There's a number of other things I could think of to improve and how to improve them, but this is getting long enough as it is.)

Overall, I'm happy with it. If you're a Close Combat fan, it's definitely going to scratch the itch pretty well. It's definitely a nostalgia-bomb from the past and predominantly stays faithful to the original enough for my tastes. I know some might complain about that aspect, that not much has changed in terms of graphics in the fight itself, but I think the style of the original is what gives it its appeal and enjoyment. 2D may have its disadvantages, but it also has its advantages. It's easier to tell where your guys are at and where to go, while also keeping the battle maps at the same amount of detail and not having to sacrifice environmental detail to compensate for being able to tell what's what and where in a wide overhead view 3D environment. If they were going to alter it into a 3D environment, it would probably just feel like another iteration of Combat Mission, rather than its own thing. If I wanted something more akin to Combat Mission for the 3D, I'd just play Combat Mission.

tl:dr - Decent iteration of Invasion Normandy. Some changes were made to the campaign maps. Mechanics largely the same. It still scratches the Close Combat itch very well.