Alright so I bought this on release day and played through probably 1/2 the campaign and I'm just now finishing it. I'm playing on normal and I swear this is one of the most difficult FPS campaigns I have ever played in my life. The AI knows exactly where you are at all times, so if there is a dude with a RPG and I pop up to fire at him even if I have moved to a different location he immediately knows where I am and nails me with a rocket. The same for mounted machine guns and such. I'm now on the part where you are running down the mountain with the mortar strikes going off and it is absolutely brutal. You have no idea when to run and when to stop so its all just trial and error, which is incredibly frustrating. Now I know the Battlefield series has always been known for its multiplayer and not its singleplayer, and I love its multiplayer. it's just so frustrating that these types of problems are left in for release, you would think they would have caught them during development.

Flank em. That is all I have to say.  
 
As for running with the mortar strikes..you stay right behind your squad leader dude. 

Yeah share your complaints. The singleplayer works, but isn't much fun, especially in comparison to the multiplayer.  You basically have to know where a handful of enemies are going to be ahead of time(the ones with rocket launchers) or you get destroyed.

I would say it's comparatively harder than other shooters out there, but manageable. What I found most hard was its tedious engagements, that all felt rather the same. I wish there was more dialogue in the singleplayer to spruce things up. 
 
And The_Laughing_Man is right, for the mortar part stay directly behind your squad leader at all times until you pass it. He does after all say "stay close" or something to that effect. 

Hmm didn't really have any more difficulty playing on normal then any other shooters :/
And yeah run exactly next to sarge during the mortar bits.

Ran next to him multiple times and got nailed every time. I finally got to the end but got nailed by another mortar, luckily I hit a checkpoint right before it happened.

that mortar thing is a bitch 
just run and pray 

" Ran next to him multiple times and got nailed every time. I finally got to the end but got nailed by another mortar, luckily I hit a checkpoint right before it happened. "

The single player certainly wasn't great, the A.I is oddly precise on occasion and it can get frustrating. That said, it's all about the multiplayer really. 

Mortar run took me about 10 times to get it. I just lucked in, I don't recall doing anything differently.

Wow gamers these days can't do anything...that is not a hard game....at all...

Played it on hard on PS3. Finished it in about 7 hours and died probably 5-10 times in that playthrough. Just got have the right mix of careful and cocky and real solid marksmanship to get it done. Hardest part was the shootout in the castle of 'Sangre del Torro' for me.

" I agree. Single player is not much fun and fairly hard even on normal difficulty. It's a shame that it's such an un-even package, with great multiplayer (much better than MW2 in my opinion) but with a single player campaign that is much worse than either Modern Warfare's. It's a shame the single player campaign sucks so much but i guess in the end multiplayer makes up for it. "

" @TorgoGrooves89 said:

" I agree. Single player is not much fun and fairly hard even on normal difficulty. It's a shame that it's such an un-even package, with great multiplayer (much better than MW2 in my opinion) but with a single player campaign that is much worse than either Modern Warfare's. It's a shame the single player campaign sucks so much but i guess in the end multiplayer makes up for it. "

Yeah, which is why I'm looking forward to Medal of Honor. DICE multiplayer with what looks like a nice singleplayer component by EA LA. "

I have to agree about the single player in Bad Company. Some of the stuff is just cheap. I noticed it got much more fun after I dumped a few dozen hours inro multiplayer and got my shooting down, though.
 
As for Medal of Honour... I have a good feeling about it.  No particular reason why, but I just have a good feeling about it.