British director Guy Ritchie says the biggest danger when making the sequel to his 2009 box office hit "Sherlock Holmes" was complacency.
Madonna's former husband was on the red carpet in London late on Thursday for the European premiere of "Sherlock Holmes: A Game of Shadows," in which he again teams up with Robert Downey Jr. as the fabled super sleuth.
Ritchie cranked up the action in his interpretation of Arthur Conan Doyle's most famous creation, and his first outing proved popular with movie-goers who spent $524 million at the global box office.
That impressive tally virtually guaranteed Hollywood would be back for more, and the sequel from the Warner Bros. studio hits U.S. and British theatres on December 16.
"I do prefer the second one," Ritchie told Reuters. "I think we just knew what we were doing more when we came to this one, we worked harder.
"We didn't want to be lazy and we knew that laziness was our enemy. It is easy to be lazy, so we had to trump it and with that comes a certain amount of anxiety and pressure."
In A Game of Shadows, Holmes comes up against his nemesis Professor James Moriarty, played by Richard Harris' son Jared who also starred in the hit TV series "Mad Men."
Jude Law returns as Holmes' somewhat reluctant sidekick Dr. Watson, whose honeymoon plans are thrown into disarray when he is called on to help avert catastrophe in 1890s Europe.
"For purists, of course, there's almost certainly too much gunplay and noise ... but this is a Holmes designed to appeal as much to the 'Transformers' generation as those steeped in his literary or even past cinematic exploits," Hollywood trade publication Variety wrote in its review.
"By that measure, Warner Bros.' new Holmes adventures must pursue a larger bounty than previous incarnations of the character. And with this improved sequel, the game is indeed afoot."
The Hollywood Reporter was less positive, saying that the action, which was "perhaps arresting the first couple of times you see it, already seems hackneyed, mannered and overworked, an affectation of diminishing returns."
Downey Jr., whose role in A Game of Shadows includes a comedy sequence in drag, was asked by reporters whether he could be considered for an Oscar for his performance.
He won a Golden Globe award for best actor in a comedy or musical for Sherlock Holmes, although his two Academy Award nominations were for "Chaplin" and "Tropic Thunder."
"Honestly, I don't really care about that stuff," said the 46-year-old. "I really like it when audiences enjoy movies -- that to me is 50 times more important than an Oscar."
Ritchie, who recently had a child with his partner Jacqui Ainsley, said he has had to juggle fatherhood and film making.
"It's funny, I feel like a dad to this film and I feel like a dad to my baby and they sort of came together hand in hand. Poor fellow has had to live with this film since he popped out you know."
Downey Jr. and his wife are also expecting a child, and asked whether he was looking forward to 2012, he replied: "Yeah I am not smelling Armageddon personally."
After battling substance abuse in the late 1990s and early 2000s, the actor's career has flourished with a series of acclaimed roles in low-budget pictures followed by a leap into superstardom with "Iron Man" in 2008 and Sherlock Holmes the following year.