Neon Kingdom is an original instrumental track for maimai でらっくす, composed by the electronic producer litmus*. It was introduced during the FESTiVAL era as part of the Metropolis Area 6 (メトロポリスちほー6) event, a narrative-driven campaign that unfolds a sci-fi conflict between the forces of Metropolis and an invading Imperial fleet. The song's flavor text sets the scene: the Imperial commander Eesh demands Metropolis's surrender and the handover of Kurohime, while the defenders, including the characters Shikoku and Kōrai, buy time for a countermeasure. This storyline context gives Neon Kingdom a cinematic, battle-ready atmosphere that complements its steady 130 BPM electronic production. The track is purely instrumental, with no credited lyrics or vocal performance. Its two-and-a-half-minute runtime is typical of maimai original compositions. Both the Expert chart (designed by Jack) and the Master chart (designed by 小鳥遊さん / Takanashi-san) are notable in the maimai community: the Expert sits at a 10+ difficulty with a 10.6 constant, while the Master chart is rated 13+ with a 13.8 constant, placing it among the more demanding upper-intermediate charts in the FESTiVAL lineup. The Master chart in particular combines 468 Tap notes with 146 Hold notes, 41 Slides, 19 Touch notes, and 43 Break notes for a total of 717 notes, making for a dense, pattern-rich experience that reflects Takanashi-san's signature design style.