A step back in time and a step down in enjoyment.
The single-player campaign in this game is nowhere near as good as that of COD4. I found myself just wishing the story was over so that I could unlock Nazi Zombies. You never really feel like you care about any of the characters in the game. I know that since this game takes place in WWII there has to be historical accuracy, but I didn't care about what happened to my character (either Russian or American). The Russian campaign is driven purely by hatred and desire for revenge. The enemy AI in this game can be horrible as well. As some reviews have said, there are times where you'll see a Japanese soldier and an American soldier standing face to face with their guns pointed at each other but then nothing happens.
As for the multi-player, it's COD4 set in WWII, which for me is a bad thing. I'll admit that I'm not the best when it comes to FPS games, but I really missed the high-tech scopes and weaponry. The one thing that I did like better was the fact that the artillery strikes actually could kill you even if you or a teammate called it in. It just seemed more realistic than the airstrikes in COD4. The addition of Capture the Flag was also a positive for the game but I didn't feel the same way about the War mode. I think Domination in COD4 was better since it forced you to hold multiple positions all at once rather than have you capture 5 locations one by one. I did like the idea of co-op and competitive multi-player, but I didn't really find it to be much fun. Rather than having your stupid AI squad mates, you have people who can fight intelligently but it doesn't make much difference since the enemy AI is still not too smart. I also wasn't too impressed with the addition of the tanks in the multi-player. It just seemed like a cheap gimmick. However, my biggest problem with the online play has to be the spawning. There were so many times where I'd get killed, respawn, and then be killed before I could even turn around to orient myself on the map. I can understand that happening on the Dome level since it's not much bigger than Shipment in COD4, but it happened all the time on the larger levels as well.
All in all, this isn't a bad game. It's based on the COD4 engine so they would've had to try really hard to screw things up. However, it just doesn't have what it takes to really draw you into the game. I just wish I had rented the game rather than purchased it. I could've gotten everything that I wanted out of it in a single weekend. I'm sure a lot of people will love this game and that's great, but I just wasn't all that impressed. Everyone's entitled to their own opinion and this is mine. Take it for what it's worth.