The campaign was solid and the developers seemed to focus more on the fun/quick run through aspect vs a technical and difficult run through. Graphics and story are solid enough.
I agree that the multiplayer felt rushed and put together and the maps are kinds of ridiculously large. Multiplayer is probably the biggest lacking part of the game. However, none of the trophies are attached to the multiplayer aspect.
Extinction is an interesting wrinkle that they threw into this COD installment. For trophy seekers, this will be the hardest because you kind of have to rely on others in your party not to mess up (i.e. challenges) and/or they have to be good as well. Thus, with the randomly paired parties online, you're very unlikely to get the trophies in extinction. It may be possible to get the extinction trophies playing it solo, but it's much harder.
All in all the game is solid with the extinction mode being the saving grace for a lack-luster multiplayer mode; good campaign mode. However, If your only focus is a modern warfare'esque multiplayer experience, don't waste your time because it's not that.