Much better 2nd half, but I put that down to Barcelona taking their foot of the pedal as much as City stepping up. That being said, the improved performance gives you brief hope for the return leg.
Aguero was comfortably your best player, and his performance is why I enjoy watching him so much, but other than that, to a man, you were outclassed (perhaps Silva aside who rarely has a bad game).
I thought Clichy was poor, Milner & Fernando looked lost in that midfield battle (if you could call it that) and Kompany was shocking. Some of his decision making was bizarre to say the least. He's always been a tad rash, but good enough to recover more often than not, however he's taken that rashness up a notch it seems and he was all over the shop leading up to Barcelona's 2nd.
On the whole though, IMO, the blame lies, again, with Pellegrini and his starting line up / setup. Not only was it a 442 again, but expecting Milner & Fernando to compete against a midfield of Barcelona's ilk is spectacularly naive. They looked lost at times in the middle of the park, which didn't help Silva & Nasri, and Barca regularly found Messi, Iniesta and Suarez alone in the hole with plenty of space to turn and run with the ball.
Hart's save from the spot could be crucial here, and hopefully Yaya can revel in the 2nd leg at the point of a MF 3 with license to run at their defence and cause problems, however I'd be extremely surprised if Barcelona didn't progress now.
A final point - I think BillyShears needs to tone down the pre match predictions.