So far I can only comment on the Campaign side of MW3.

I normally am pretty happy with the campaign side of Call of Duty as they're generally action packed and exciting to play through. For clarities sake, I've completed the entire campaign on Veteran mode. With MW3, they changed the formula by mixing in sandbox like levels similar to Warzone in which you need to complete three objectives in order to complete the level. The sandbox structure allows you to complete the three objectives in whatever order you wish and you can obtain new items/weapons through boxes to help you on your way. It essentially is the same structure as Warzone except that you're dealing with bots rather than players and on top of that they've sprinkled a little story line dust over it.

While the above may sound fun, the reality of it is that those levels are incredibly boring and very easy to complete. You're basically able to just sprint from objective to objective with little opposition (even on Veteran Mode). Only completionists will want to bother finding and unlocking every weapon in the map. So far it doesn't look like those weapons will carry over to online play either so I don't see a point in going back to look for more boxes.

In between those Warzone like campaign maps, you will also have more in depth levels which follow the original linear structure where you're being guided through the level by your fellow soldiers. I personally find this to be a lot more immersive in comparison to the sandbox levels.

As far as the story goes, it feels....short and unsatisfying. The story doesn't get wrapped up and instead leaves you on a cliffhanger. Spoiler ahead > There is a major character death at the end which honestly feels like it only serves to remind the player that people can die during these missions. The character that dies doesn't get a satisfying or heroic ending. They just get offed and that's it. They went for shock value but it honestly just feels kind of like a slap to the face to the people who grew somewhat attached to the character over the years.

All in all, I would say that this campaign is the weakest in the entire series so far. It's not worth buying the game if you're only planning on playing the campaign though I assume most people won't anyway. I do sincerely hope that the multiplayer delivers.

I feel I have enough hours played now to update my feedback. While I still agree with what's mentioned above, the game is still very enjoyable on the Multiplayer side. I've spend hours playing TDM (Hardcore mostly with every now and then some breaks on Ground War).

When it comes to shooting mechanics, I'd say that MW3 is the best one that I have personally played. It's fluent, it's fast paced (but not too fast). Overall the movement feels very nice. Unlocking attachments is annoying as I'm used to simply unlocking attachments whilst leveling my weapon. Certain attachments are locked behind different guns so if you're looking for the ideal build, you may have to level up several weapons. While annoying, it does force the player to explore different guns so I can understand why they've opted to do this. XP events and CoD Zombies can definitely speed up the entire process.

I should note that Multiplayer (specifically Hardcore) can be rather sweaty. This suits me perfectly fine because I consider myself an experienced player. Casual players may find themselves getting dunked on frequently and I've already encountered tons of players who accuse other players of hacking. I can honestly say that I haven't encountered any blatant hackers myself save for maybe one or two. I am however accused of hacking a lot but this may simply be because of cross play. PC players have an advantage.

As for CoD Zombies, I've played a bunch of that when it first launched with a friend of mine. Playing it was fun while it lasted but it grew flat rather quickly. The story line that they've connected to it leaves a lot to be desired. Playing the same map over and over again became boring as well. Quests to progress through the story are structured in such a way that you can link several quests in one game session but you can only look ahead so far. This means that you are obviously forced to extract and restart several times. I understand it's to pace the player somewhat but I am of the opinion that the game play should speak for itself to keep things fun. For the completionist, doing these quests can be considered challenging and fun but for players like me that just want to grind our way through it to get the special skin and blast some zombies in the process, it's annoying.

With all of the criticism that I've mentioned above, I still find myself playing several multiplayer matches almost every day. It's just a great way to unwind after work. Because of that, I will recommend this game to players that are looking to do the same thing.