was not supposed to. Stander used graphical effects to emphasize major decisions, such as moving or colored text and character animations. He accomplished this by programming the script to affect other areas of the game upon reaching certain points. His initial intention was only to add polish, but he began to experiment and added elements such as distortion effects and screen-shaking. Music Katana Zero synthwave score, which blends Chicago house, electronic music, and synth-pop, was composed by Bill Kiley and Thijs "LudoWic" Lodewijk, with additional music by Stander. Kiley had collaborated with Stander in the past and Stander recruited him to work on Katana Zero at the beginning of development. Lodewijk, who had never composed a video game, became involved in 2015, after Stander found his YouTube channel and recruited him to write a single track. Stander then asked if he could use music from Lodewijk's "jams" (improvised recording sessions Lodewijk had uploaded to his channel); the jam that first drew Stander's attention to Lodewijk, "Jam #12", was used as the boss theme. Lodewijk composed a track specifically for Stander after joining the project, but Stander told him to compose as he normally would. Kiley and Lodewijk looked to 1980s electronic music for inspiration since the game's themes—including drug use and the effect of war on a nation's spirit—were relevant in the 1980s in the aftermath of the Vietnam War. They originally worked separately, as Stander wanted Kiley to write muted music for story-driven scenes and Lodewijk to write energetic music for the main levels. According to Kiley, "As the project progressed we gleefully broke this rule and ended up writing music for levels and story scenes all over the place." Kiley and Lodewijk attempted to reflect Zero's changing psyche and moods in their music, such as when Zero experiences Chronos withdrawal and snorts cocaine in a limousine. Kiley drew influence from the work of Gary Numan, Yellow Magic Orchestra, and Vangelis, and sought to evoke the feelings of 1980s action films. Stander sent Kiley and Lodewijk screenshots, concept art, and notes describing the atmosphere he was aiming for, occasionally alongside an existing piece of music for reference. Lodewijk explained they would send their initial composition to Stander, leading to a series of exchanges that resulted in the final track. Some tracks ended up in different levels than intended, and for certain levels and dream sequences, Lodewijk wrote two tracks