Jeremy Heilman’s review published on Letterboxd :
This biopic predictably deals with Sellers’ acting genius by suggesting that he was unable to function in real life. Portrayed here by Geoffrey Rush and a slew of prosthetics as an impulsive egomaniac, this Sellers has been conceived as a man without any personality at his core. Given nothing substantial to play, Rush performs series of hollow physical impersonations. It’s a film that traffics in the shallowest form of celebrity gossip, emphasizing bad behavior to no particular end (yet still convincing itself it’s vaguely prestigious). As such, a tremendous amount of time is spent emphasizing Sellers’ marital dysfunction, but little insight into why he was loved in the first place emerges. Sellers is a void, yet he’s not productively used to make a statement about the nature of identity or the act of performing. Hopkins directs largely by choice of soundtrack. The conceit of having Sellers adopt the key personae of his life remains a gimmick that only distances us from the subject. Nothing featuring Miriam Margolyes is a complete disaster, but this comes close.