if the filmmakers were worried the story would n't work without all those gimmicks 
(ROOT (SBAR (IN if) (S (NP (DT the) (NNS filmmakers)) (VP (VBD were) (ADJP (VBN worried) (SBAR (S (NP (DT the) (NN story)) (VP (MD would) (RB n't) (VP (VB work) (PP (IN without) (NP (PDT all) (DT those) (NNS gimmicks))))))))))))
(ROOT (SBAR (IN ) (S (NP (DT ) (NNS )) (VP (VBD ) (ADJP (VBN ) (SBAR (S (NP (DT ) (NN )) (VP (MD ) (RB ) (VP (VB ) (PP (IN ) (NP (PDT ) (DT ) (NNS ))))))))))))