13 Sentinels: Aegis Rim

13 Sentinels: Aegis Rim is a video game where players take control of thirteen different characters, who interact with each other to build a larger narrative. The battle system of the Destruction mode takes the form of a real-time strategy scenario, with up to six chosen characters using Sentinels to fight off waves of Kaiju defending a terminal. Battles pit Sentinels against Kaiju with differing strengths and abilities such as flight or extra defense, requiring one of the four Sentinel types; some Sentinels are strong against flying enemies, while others do better against large ground-based forces. They also have different attack ranges and movement speeds. Sentinels have at least one basic attack that costs nothing, and additional abilities that cost a resource called EP; EP can be recovered by defending. After acting, each Sentinel has a cooldown timer before it can act again. Damage can be repaired by Sentinel pilots, but this requires leaving the Sentinel and leaving them vulnerable to attack. The player can also trigger limited-use "Terminal Commands", special field-wide abilities such as an EMP which use up a dedicated energy gauge. Characters level up with experience points and gain passive bonus effects, while Sentinel abilities and attributes can be raised using Meta-chips gained during battles. Analysis takes the form of an index where event scenes and information on people, items and concepts are archived. Mystery Points, earned through Destruction mode, are used to unlock new index entries in Analysis. As the player advances, character narratives are locked off until something else has taken place in another section of the game. These unlock conditions can include unlocking entries in Analysis, advancing stories in Remembrance, or tackling particular battles in Destruction. ==Synopsis==

Setting and characters 13 Sentinels is primarily set during a fictionalized version of 1985 in the Shōwa period, but also jumps between 1945 during the later years of World War II, 2025, 2065, and the distant future of 2105. A recurring location is Sakura High School, which multiple characters attend across different time periods. There are several notable supporting characters. Chihiro Morimura is both the school nurse and the teacher for Kurabe and Fuyusaka's class. Tsukasa Okino is a genius student with deep knowledge of the Sentinels, who frequently cross-dresses as a girl. Chihiro is a mysterious girl who Miura considers his sister but who later accompanies Gouto during several sections. Kyuta Shiba is one of Juro's best friends, but possesses a hidden agenda. Erika Aiba is a student who tags along with Takamiya as they solve mysteries surrounding the Sentinels. Tamao Kurabe is a woman from the 1940s who closely resembles Aiba. Tetsuya Ida, while ostensibly a part-time instructor, is the chairman of the covert Special Investigations Unit (SIU) in 1985. The small robot BJ accompanies Natsuno on her journeys through time. Fluffy, a talking cat, strikes a deal with Megumi to save Juro. Miyuki Inaba is a famous idol within the 1980s period. Plot In 1985 Japan, Kurabe, Fuyusaka, and Amiguchi experience shared dreams, either of themselves fighting previous wars against the Kaiju or of what appear to be older versions of themselves in the future. Juro Izumi, the original version of Kurabe, uses extreme measures to change events and is dubbed Prisoner 426, going on to use the avatars of Aiba, Fluffy and Shiba to further his plans and ending up directly aiding the thirteen pilots. The current Morimura—a former associate and lover of Izumi—is determined to trigger Operation Aegis, which will cut off Universal Control from the Deimos while trapping them in the ruined simulation. She is killed by the preserved personality of the original Chihiro Morimura, who exists in the avatar of Miura's sister. Initially pessimistic of their chances, she is persuaded by Gouto to aid them. Fuyusaka is revealed to be another avatar of Morimura. In Hijiyama's route, it is revealed that the originals in the space colony eventually descended into violence over resource disputes. Each arc concludes with the protagonist joining the final battle. A secret cutscene shows self-replicating machines sent into space by Project Ark have colonized at least one other planet, where the game's events are repeating with some differences. ==Development==

13 Sentinels was developed by Vanillaware, a Japanese game developer who also worked on Odin Sphere, ''Dragon's Crown and Muramasa: The Demon Blade, notable for their usage of 2D art in an industry predominated by the usage of 3D graphics. Vanillaware founder George Kamitani, who also directed Odin Sphere and Dragon's Crown'', returned to serve as director for the game while handing the character design duties to Yukiko Hirai and Emika Kida. Full production began in the summer of 2015 following the completion of remakes of Muramasa (Muramasa Rebirth) and Odin Sphere (Odin Sphere Leifthrasir). Based on feedback from Prologue, the development team were able to make adjustments and additions to the main game. Scenario The concept for a story featuring multiple protagonists was drawn from the long-running television series Chūgakusei Nikki. The narrative structure also drew inspiration from Western thriller fiction. Kamitani wanted to create a mecha-themed story for a modern audience, as many of the most memorable genre works (Mobile Suit Gundam, Neon Genesis Evangelion) were by that time several decades old. At one point, each of the thirteen protagonists had twelve possible story paths, making for a total of 165 possible variations. Due to the production timeline and the need to reveal the story mysteries, Kamitani had to cut a lot of planned optional comedic and bonding scenes between characters. Several of the surviving routes went through extensive revisions, with some planned scenes such as a coffee shop location being cut, but a key surviving theme that came with its shōjo manga inspiration was romance. Kamitani cited several storylines as technically difficult to write, such as Takamiya's detective-themed narrative, Shinonome's amnesia plotline and Ogata's train sequences. Amiguchi's story was the most straightforward and thus easiest to complete, while the dark tone of Yakushiji's narrative often left him depressed. The battle level designs were directly based on the graphic design of Gunparade March and Fantavision, with the blue-hued character portraits being based on the monitor displays and lighting of Alien. All other aspects of the game's sound design were handled by Masaaki Kaneko. The song was written by Sakimoto. Compared to his earlier work with Vanillaware, Sakimoto worked more on keeping a unified musical image. The music was themed around techno, but the team worked to keep melodic balance in the score. Its theme was "juvenile", with Sakimoto needing to redo his early work with Kamitani's help. Though Kikuchi and Watanabe were new to Vanillaware titles, both Kudo and Kaneda had worked with the studio on Odin Sphere and Muramasa. Kudo, Kaneda and Kikuchi handled the battle tracks based on Sakimoto's direction for tracks which changed based on the player's progress through the stage. A recurring need for the score was to balance electronic and orchestral elements throughout the score. The two gameplay modes had different musical styles; the adventure sections used "analog" sounds and a focus on atmosphere, while battles made heavy use of electronic elements and rhythm. Some of the earlier tracks overtly used Showa-style composition, but as the setting was already heavily based around the Showa period, the music shifted to be less period-specific. Another difference compared to earlier Vanillaware projects was that more of the tracks were designed with a specific story-based theme, such as shopping in the high street. Due to the changes made to the game, the themes consequently needed a lot of adjustment during production. The placement of some songs within particular scenes, such as a sombre piece accompanying a comedic moment, were done by Kaneko based on his interpretation of a scene. The album included the full version of "Seaside Vacation", and versions of the battle tracks which ran through all their variations before segueing into the victory theme. It was also released as a worldwide digital release on iTunes. The album was described by Kudo as "a musical expression of another aspect" of the game. A further album featuring tracks from a 2023 orchestral concert was released in Japan on May 10, 2024. All three albums were released worldwide on streaming services in June 2025. Voice acting Voice recording for the script ran concurrently with the scriptwriting and revision process, with six different recording sessions for various actors happening during production. Voice recording ran on until very close to the game's retail release. Several of the actors were fans of Vanillaware's titles, and enjoyed voicing the characters. Due to the plot point surrounding Fuyusaka, Morimura and Chihiro, all three shared the same voice actress: Atsumi Tanezaki. As scenes were recorded out of story order, the recording team needed a dedicated worksheet showing which scene called for what emotion so the actors would not make any serious mistakes with characterizations. Kaneko had a difficult task balancing out the music and dialogue in different scenes, made more complicated by the scenario's complex structure. Full voice acting, including the Thought Cloud dialogue sections, was a later addition chosen to promote player immersion. Due to this task, Kaneko had to carefully sync voice clips with keywords from the Thought Cloud so that it would not sound like random noise, along with filtering the music and environmental effects so the voice work came through clearly. ==Release==

13 Sentinels was announced at the 2015 Tokyo Game Show. Prior to the announcement, the game was teased in a preview video in July as a collaboration project between Atlus and Vanillaware following the public reveal of Odin Sphere: Leifthrasir. The delay and cancellation of the Vita version occurred in November 2018. 13 Sentinels: Aegis Rim Prologue was released in Japan on March 14, 2019. It came in both a standalone edition and a special edition which included artwork and a mini soundtrack. Prologue also featured a short teaser for the company's next project, later called Unicorn Overlord. A demo that allows players to access the first three hours of the game was released in Japan on October 30. The game was released in Japan on November 28, 2019. A manga anthology based on the game, featuring stories from each character's perspective, was released on September 10, 2020. 13 Sentinels was originally set to be released outside of Japan on September 8, 2020, before being delayed until September 22. Pre-orders included an artbook, with limited quantities for the game's physical edition. The game was published in the region by Sega. The team were beginning English dub recording when the COVID-19 pandemic disrupted their schedule. The voice acting took a collaborative effort between Atlus, Sega, Vanillaware and Basiscape. A Nintendo Switch version was released on April 12, 2022, in the West and two days later in Japan. An August patch added the Switch port additions and updates to the PS4 version. The Japanese release was also patched to include the English dub. == Reception ==

13 Sentinels: Aegis Rim received "generally favorable" reviews according to review aggregator website Metacritic. These low sales were blamed by Kamitani on the game's blend of genres, difficult production, and releasing alongside other popular titles. While initial sales were low, positive word of mouth from both players and other industry figures caused sales to increase, resulting in stock shortages. It remained in the top 30 best-selling titles into January, with total physical sales of over 59,000 units on PS4. By this point, physical and digital sales had reached 100,000 units. In their fiscal report, Atlus said that 13 Sentinels: Aegis Rim exceeded their sales expectations. Following its worldwide release, the game had sold over 300,000 copies by January 2021. By August 2023, physical shipments and digital sales reached one million copies. The game won the awards for "Best Scenario" and "Best Adventure Game" at the Famitsu/Dengeki Game Awards 2019, and it was nominated for "Game of the Year", "Best Graphics", and "Best Rookie Game". It received a nomination in the "Media" category for the 51st annual Seiun Awards in 2020, the only video game nominee that year. The game was also nominated for "Best Narrative" at The Game Awards 2020. In IGNs "Best of 2020", 13 Sentinels: Aegis Rim was one of the nominees in their "Best Adventure/Puzzle" and "Best Video Game Art Design" categories. During the 24th Annual D.I.C.E. Awards, the Academy of Interactive Arts & Sciences nominated 13 Sentinels: Aegis Rim for "Outstanding Achievement in Story". ==References==