It doesn't take a Holmesian level of deduction to realise that the titular protagonist of Roman Coppola's second feature isn't a million miles away from the troubled star who plays him; for all intents and purposes, the headcase calling himself Charles Swan III (or Charlie, as his friends refer to him) might as well be Charlie Sheen, who no doubt saves money on therapy bills by working through some of his personal issues on screen here. Swan is a hotshot graphics designer in the 1970s, and when his girlfriend Ivana (Katheryn Winnick) dumps him, his life crashes down around him. Caught between two extremes - of wanting to win Ivana back and vowing never to speak to her again - Charles meanwhile seeks counsel in his friend Kirby (Jason Schwartzman) and manager Saul (Bill Murray), and tries to contend with nagging health issues, as well as a fleet of haunting visions which push his psyche further to the limit. In a sense, such a spare, free-wheeling film, even with its flaws, is the perfect vehicle for a pronounced real-life character like Sheen. He seems surprisingly up for the workout and is well-cast in the lead role, even if the film doesn't seem to want him to visit any particularly challenging places, mostly settling for a slew of self-consciously quirky, surreal asides, more often than not dealing with Swan's various perversions. The problem with this is that just as Coppola's story seems to naturally settle down, he railroads it back into Loonyville with another weird interjection, which is fun to begin with but ends up denying the characters any palpable agency; the sudden climax which miraculously resolves everything is bereft of anything even remotely resembling an arc. Though in theory this is a relatively undemanding 80-minute sit, Coppola's fidgety approach has by the credit roll become rather annoying, although the final shot is admittedly rather snazzy. The moments which do hit the mark are almost exclusively thanks to the talented cast roped into it rather than the script; Schwartzman gets to rip through several memorable dialogues, while it's Bill Murray who delivers the film's strongest moments - a bedside conversation with Charlie dispenses with the gimmicks and just shoots for flat-out honesty. Unfortunately, Coppola doesn't confront the reality of the heart's complicated matters nearly enough; he's too busy rolling cars down hills and constructing elaborate set-pieces. As for Sheen, has he still got it? Absolutely, though some will argue that the controversial actor is simply playing himself, as he seemingly has in so many recent roles. Nevertheless, his screen presence is undeniable, as it provokes the feeling that he might be worthy of a more becoming vehicle in the future. As for the rest of the cast, Katheryn Winnick, a character actress with a CV ranging from starring roles in terrible horror films (Choose) to bit-parts in major Hollywood features (Love and Other Drugs), gets a major push here, proving herself more than just a pretty face, standing ably alongside the veterans she co-stars with, such as Patricia Arquette (playing Charlie's frizzy-haired sister), and Stephen Dorff (who appears to play himself in a brief cameo), as well as up-and-comers Aubrey Plaza and Mary Elizabeth Winstead. The irreverent tone is welcome, but a film with a cast this grand really should bite harder. Charlie Sheen proves he still has something to contribute, but like us, he's defenceless against Roman Coppola's inchoate script. A Glimpse Inside the Mind of Charles Swan III is available now on VOD and on limited theatrical release in the US from Friday.