works on some levels and is certainly worth seeing at least once . 
(ROOT (S (VP (VBZ works) (PP (IN on) (NP (DT some) (NNS levels)))) (CC and) (VP (VBZ is) (ADVP (RB certainly)) (ADJP (JJ worth) (S (VP (VBG seeing) (ADVP (ADVP (IN at) (JJS least)) (RB once)))))) (. .)))
(ROOT (S (VP (VBZ ) (PP (IN ) (NP (DT ) (NNS )))) (CC ) (VP (VBZ ) (ADVP (RB )) (ADJP (JJ ) (S (VP (VBG ) (ADVP (ADVP (IN ) (JJS )) (RB )))))) (. )))