Worlders is the ending theme song for the animated film 劇場版プロジェクトセカイ 壊れたセカイと歌えないミク (Project Sekai: A Miku Who Can't Sing), composed and written by Jin (じん) and arranged by TeddyLoid. Released as part of the movie's original soundtrack in 2025, the song brings together an extraordinary vocal cast that includes all six virtual singers, Hatsune Miku, Kagamine Rin & Len, Megurine Luka, MEIKO, and KAITO, alongside the full 20-character voice actor ensemble from Project Sekai, spanning every unit in the game: Leo/need, MORE MORE JUMP!, Vivid BAD SQUAD, Wonderlands×Showtime, and 25-ji, Nightcord de. The track arrived in maimai でらっくす CiRCLE on October 16, 2025, as part of a coordinated three-game launch that also included CHUNITHM X-VERSE and ONGEKI Re:Fresh, a rare simultaneous cross-title drop among SEGA's rhythm game lineup. In maimai, the MASTER chart (level 12+, designed by カマボコ君) takes rhythmic inspiration from the Project Sekai MASTER difficulty of the same song, making for a familiar yet fresh mapping experience. The Expert chart (level 9+, designed by Luxizhel) offers a distinct interpretation. At a steady 137 BPM, Worlders sits at a moderate tempo, though the 12+ MASTER delivers a dense challenge with 532 total notes, including heavy Slide and Break clusters that test accuracy and speed.