Complex sentence: As he felt that "I Vampiri" was unpopular in Italy due to the Italian audience feeling that Italians could not make high quality genre films, the cast is credited under English-language aliases in the films promotion and credits.
Split into simpler sentences: As he felt that "I Vampiri" was unpopular in Italy due to the Italian audience feeling that Italians could not make high quality genre films. The cast is credited under English-language aliases in the films promotion and credits.