> many people and critics << showed >> it as one of the best superhero movies Critics and people don't "show" a movie. The theater shows it, the critics and people review it. > and I really think it's good, but not at the level it claims to have or at the level of criticism, A movie can't claim it's good. Viewers or critics can. > I like the movie but it seems to me that << it >> should have at least 40 minutes less in its duration, To make this sound more natural you could just say "I thought it should have been 40 minutes shorter."