Ryan Reynolds personally talked to Mariah Carey for the rights to use her song "Fantasy" in the film. The rights issue was a little complex, however, as the song was directly sampled from the Tom Tom Club hit, "Genius of Love" (1981), the live version of which can be found in the Talking Heads concert film, Stop Making Sense (1984). Tom Tom Club was essentially Talking Heads without its leader, David Byrne. Samples of Genius of Love have appeared in over thirty songs attributed to other artists.
Shortly after Guy buys his new shoes, a gin bottle-shaped power-up on the floor titled "Subtle Product Placement" is visible over his shoulder. It's likely a reference to Aviation American Gin, which Ryan Reynolds had a stake in and maintains an ongoing ownership interest.
A map of Free City, the city that the game in the film takes place in, is actually a map of Portland, Oregon. The "stash house" that Jodie Comer's character wants to break into is shown as being located in Portland's Forest Park.
Shawn Levy originally read the script in 2016 - and passed on it. He was persuaded to reconsider by his friend, Ryan Reynolds.