“Americana” is one of those there’s-a-movie-in-there-somewhere movies. Its interlocking narratives of various characters seeking a valuable Native American artifact in rural South Dakota hints at a darkly comic revisionist cowboys and Indians western though writer/director Tony Test can never quite finesse it into anything so substantial. His tone often veers, a campy crime drama striving for barbed satire, or a B-movie straining to be an A-list movie with something to say, just never quite sure how to say it, building to a big multi-character shootout in which gunfire becomes a wannabe spackle for all those tonal holes. Tost was the show runner of the second season of “Poker Face,” but while that show also tries out different tones from episode to episode, Natasha Lyonne’s unique air helps meld it together. And though Sydney Sweeney is featured on the “Americana” poster, she is merely one part of an ensemble, and her character, like the others, is defined more by a gimmick than an inner life. She has a stutter, and Lefty (Paul Walter Hauser) is a righty, and a young boy (Gavin Maddox Bergman) claims he’s in the reincarnation of Sitting Bull, the last one a set-up with no punchline. The ever-impressive Hauser gives the one performance that seems most at home, believably rendering a big-hearted sap who can’t help walking straight into a spiderweb, which is where everyone in the real-life cast ends up, like it or not.