United thumped the champions 4-1 at Old Trafford on Saturday, with all the hosts' goals coming in the first 45 minutes.
Mourinho told MUTV: "Yes. Yes, that's what we want to become.
"We were much more aggressive. We pressed higher. The team reacted quicker when the ball was lost. We played fast football. (Juan) Mata helps us do that. Marcus Rashford and Jesse Lingard offers us great intensity.
"And Zlatan (Ibrahimovic). The striker doesn't score one goal in four, but he played superbly."
He added: "The reality is we played very, very well until the game was closed. After that... we won."