Mannion received an Australian Directors Guild award nomination for his film Anima, which secured grants from Screen Australia and Screen NSW. Anima had its international premiere at the prestigious Clermont-Ferrand film Festival and TV premieres on Canal+ and SBS.
From 2014 to 2015 Mannion joined US production company Benderspink (A History of Violence, The Hangover) to write and develop feature films Polybius and Battlesim.
Before working with Benderspink Mannion directed and produced two successful Kickstarter campaigns (supported by former Australian of the Year Patrick Mcgorry, and Gold Logie-winning actor Samuel Johnson) He raised over $200,000.
Currently, Mannion is developing a Cold War psychological thriller, Gestalt.