Spoilers ahead, you've been warned.
I completed the game in 11 hours (with breaks) on Veteran difficulty, and I would give it a solid 8.5. Here are my detailed impressions:
Let me start with the fact, that I completed the game on Veteran, and it was the worst decision of my life. I completed almost every CoD game on Veteran, and I love the challenge, but this game was just unfair. Every second enemy had this awful armor, grenades flew all over the place, your team's AI is nonexistent, like literally. I've seen Ghost fighting one normal enemy for two minutes, Rodolfo running in circles between enemies, doing nothing, Alejandro missing the shot during "you kill the left guy, right one is mine" section, and more. Enemies lasered me with shotguns, from miles away, like rooftops away, through multiple walls. They always knew my position, and they often one shotted me, before I could see them. Let's say I'm a Veteran of Veteran (heh), but this was disgusting.
Moving forward, the visuals in this game are beyond me. This is literally the best looking game I've ever seen, it looks photorealistic, Amsterdam section looks like real life.
I adore our soldiers, they are really well written, Alejandro might be my new favorite character. I was skeptical with Ghost at first, as for me, he was never really too special. In OG MW2 he was the guy with a cool mask, that's it. In this iteration, he started like this really edgy guy with a secret identity and probably some really dark past, and I didn't like it, at all, but later in the game, they showcased his character more, and he started to grow on me. I totally expected them to show us his face, but I'm glad they didn't, we've got teased badly, tho. I really liked the "side" characters, like Diego and Valeria, too. Also, I totally expected Rodolfo to reveal as Roach later in the game, but it didn't happen. I was also really glad to see Farah, as I enjoyed her character very much.
Now that I talked about the cool characters, I absolutely hate the villains in this game. Shepherd's motive doesn't buy me, at all, I preferred him being a straight-up traitor in the OG game, and the fact that he fled is funny to me. Hassan almost made me fall asleep, and even though we chased him for the most of the game, I feel like he was barely in it. Graves was the best of the three, but nowhere close to being good. That said, CoD had really legendary villains over the years, so I kinda accept, that it's hard to beat them, but I feel like they haven't even tried. Their deaths, tho, oh boy were they awful. After the worst fight, maybe ever (at least on Veteran), we don't even see the body of Graves. I laughed out loud at this, but at least we had awesome dialogues between him and Soap during the fight. Hassan's death was even worse in my eyes. CoD always had these memorable endings with totally batshit crazy stuff going on near the end. This time, he captures injured Soap after this awful stealth crafting section, and you just put a bullet in his head with a sniper, the end, lol.
I appreciate the gameplay of the missions, a lot of them felt like real military operations/special ops (I mean, I felt like they could really happen irl, while nothing in the OG trilogy seemed like that). I actually liked all the gimmick missions. The convoy was insanely good, cameras mini-game was super fun, "All ghillied up" style mission was awesome, with a lot of options to choose, the callback to ghosts from the last mission was also really well executed, "Alone" mission was great, I really liked the crafting gimmick, too bad it didn't work in the last mission, at all. They were all really nice, and I loved the diversity in gameplay they offered.
I enjoyed all throwbacks to mw2, like Ghosts saying that Shepherd "burned them", reuniting with Price in prison, OG ghost masks and a lot more. I totally didn't expect them to make a "no russian" reference, and for sure I didn't expect a tease for it, but I'm all in for it, and when I think about it, it wasn't that unlikely to happen. Furthermore, I'm glad Makarov is coming back, at least one good villain is more than needed, I hope he turns out better than this Shepherd.
So yeah, excluding disappointing villains and awfully balanced Veteran difficulty, the game was pretty chad, and I had a blast with it. Below are my small thoughts on individual missions:
"Strike" - A cool intro, I guess. It shows how stunning the graphics are, the canyon looks photorealistic, with 4k and HDR it literally looks like real life.
"Kill or capture" - Another beautiful looking mission, really fun to play, seemed to me like an actual military operation, just a little over the top, a lot of "clean house" style, it was a really good start. Ghost introduction was a little too edgy, tho.
"Wetwork" - Fun, but short, nothing too special.
"Tradecraft" - Another "fun, but short" one, but with absolutely stunning visuals, it's actually insane how good they are.
"Borderline" - Awesome mission, I started to like Alejandro since the beginning, "clean house" style gameplay, again, felt like an actual operation, too. Really impressive stuff, especially towards the end of the mission.
"Cartel Protection" - Another great mission, a little more action this time, stunning visuals, the cliffs and river sections were something fresh, and it worked really well.
"Close Air" - I didn't expect AC-130 mission, but Oh Boy, I missed it. Really appreciated mission, was really fun, except the civilians part.
"Hardpoint" - More of AC-130, nothing wrong with it.
"Recon by Fire" - Awesome mission, all ghillied up style, great atmosphere, and fun gameplay, I loved the freedom and variety of options in this mission... If only it wasn't that hard on Veteran, I spent hours on this mission.
"Violence and Timing" - My favorite mission, I liked everything about it since the very beginning, a lot of crazy action, hijacking cars, dodging mines, shooting while driving, total mayhem. The realistic part pretty much died there, but it was fun as heck. Also, glad to see Farah, she was a great character.
"El Sin Nombre" - A stealth mission with its own gimmicks, I actually liked it a lot, Diego and Valeria were pretty impressive characters.
"Dark Water" - Awesome mission with a lot of action, the ship part was awesome in my opinion!
"Alone" - I actually loved this mission, which seems to be an unpopular opinion. It was brutal on veteran, I decided to do the achievement without firing a gun, so it was even harder, but I think it really added to the experience. I actually had to use all the stuff I've found, and think a lot about my actions. Dialogues between Soap and Ghost were gold, I actually didn't like this iteration of Ghost at all before that mission, he just seemed like an edgy soldier with sEcReT identity, but this mission really added to his character. I really appreciate the callbacks to the OG MW2, too. The only stupid part was the crafting animation repeating all the time, otherwise it was a really fun mechanic.
"Prison Break" - Nice mission, the cameras mini-game was fun as heck, a lot of good action happened, and I find it a nice callback to the OG MW2 mission, where you also reunite with Price in prison. Too bad, it was almost unbeatable on Veteran difficulty.
"Hindsight" - A flashback... Cool, I guess? To be honest, I didn't really like the motivations of this iteration of Shepherd, but it's just my opinion.
"Ghost team" - I find the whole ghost masks idea silly as heck, but at least we got the OG ghost for a while. Otherwise, it was a really good mission, a lot of action, awesome stuff with Price in helicopter, a lot of diversity, just that tank section was awful. Almost unbeatable on Veteran, friendly AI was nonexistent in it, too, and Graves' death was awful, not satisfying at all, but at least we had that fun dialogue between him and Soap.
"Countdown" - Nice mission, a good callback to Ghosts, really fun, except it was once again, hard as heck on Veteran, and the last segment with crafting was pretty weird. It worked in "alone", but it was pretty meh in this one. I find Hassan's death pathetic and not satisfying at all, but he was a boring villain, anyway.