It would be easier to admire the can-do philosophy of Robert Rodriguez – he writes, directs, shoots and edits most of his movies with digital-video technology – if the results were as ingenious as the process. This third installment in his series about a mariachi-turned-assassin (Antonio Banderas, joined this time by Johnny Depp), looks slightly better than Spy Kids 3-D, but not much – it’s a big-time action movie crying out for the sheen of celluloid.