13 Sentinels: Aegis Rim (NSP, XCI) ROM + v1.10 Update

13 Sentinels: Aegis Rim is a 2019 video game developed by Vanillaware and published by Atlus. It was released for the PlayStation 4 in Japan in November 2019 and worldwide in September 2020, with a Nintendo Switch version released in April 2022. The game is divided between side-scrolling adventure segments and real-time strategy (RTS) battles and follows thirteen high-school students in a fictionalized 1980s Japan who are dragged into a futuristic war between mechas and hostile Kaiju in a nonlinear narrative.

Director and writer George Kamitani conceived the game in 2013 following the completion of Dragon’s Crown, originally pitching it for a toy line. 13 Sentinels began production two years later, discarding the toy line element under Atlus. The production proved challenging for Vanillaware, as the studio dealt with workload and development challenges. Contrary to previous works, Kamitani both worked on the script alone and handed character design duties to Yukiko Hirai and Emika Kida. Hitoshi Sakimoto and his studio Basiscape, who handled the music for Vanillaware’s past games, revisited their roles.

Originally scheduled for a 2018 release on both the PlayStation 4 and PlayStation Vita, the game was delayed until 2019 with the Vita version being canceled. The English localization by Atlus West proved challenging due to the COVID-19 pandemic. It saw a slow start in sales upon its release in Japan before eventually exceeding Atlus’s expectations, with shipments and digital sales reaching one million units by 2023. Critical reception has been generally positive, with praise going to its narrative and art design, though several reviewers faulted the RTS segments as the weakest part of the game.

GAMEPLAY

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 gameplay is split into three sections. They are Remembrance, with exploration and dialogue taking priority and advancing the narrative; Destruction, where characters equip mecha and engage in battles against enemies called Kaiju; and Analysis, a glossary that documents event scenes and important items and characters.

During the adventure game-style Remembrance segments, the player explores two-dimensional (2D) side-scrolling environments, interacting with elements of those environments in a non-linear manner. Several elements move in real-time regardless of the player’s actions, and choices can be made which alter the outcome of some scenes. Keywords spoken by characters and obtained items are added to a Thought Cloud database, which can be accessed to trigger both internal monologues and initiate new dialogue. Once learned, keywords are carried over into other earlier or parallel scenes, which in turn unlock further story routes and options. The character stories are tracked with a flowchart, with players able to jump between scenes to try different keywords from the Thought Cloud. If a wrong choice is made during one section, the game rewinds to the beginning of the day so players can select the right choice. To reach that point faster, events the player has already seen can be fast-forwarded.

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. The terminal’s health is determined by which units are in place, and if all units are defeated, the hub is overwhelmed and the game ends. Gameplay can be paused, allowing for Sentinels to be moved and actions such as combat and support abilities to be carried out. The section is completed when the hub is successfully defended against all waves. 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.

The 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.

PLOT

In 1985 Japan, Kurabe, Fuyusaka, and Amiguchi experienced shared dreams, either of themselves fighting previous wars against the Kaiju or of what appear to be older versions of themselves in the future. They are later seen by Morimura, who Kurabe learns is administering an unknown medication to some students; Kurabe is referred to in Morimura’s notes as “Juro Izumi”, an identity he cannot remember. Takamiya is blackmailed by SIU member Ida into monitoring students at Sakura High School. Takamiya’s friend Minami finds a robot called BJ; assumed to be an alien, BJ is an AI robot from 2105 searching for its Sentinel. Yakushiji, from 2025, is approached by Fluffy, who says he can bring back “Izumi” if she shoots select people with a special gun. Gouto and Shinonome both work for the SIU, recruiting Kisaragi in 2025 after the Deimos attacked her period. At a later point, an amnesiac Sekigahara wakes up next to the murdered Morimura, ending up being pursued by SIU operatives. In 1945; Miura and his little sister Chihiro live with Tamao Kurabe and are friends with Hijiyama and newcomer “Kiriko Douji”, later revealed to be the cross-dressing Okino. Shortly after Okino took Hijiyama in 1985, the Deimos attacked in 1945. Tamao vanishes upon being “killed”, Gouto kidnaps Chihiro, and Miura accidentally travels to 1985 using a Sentinel. Each playable character has dedicated intertwining story arcs, revealing more about individual pieces of the plot.

It is gradually revealed that rather than periods, the protagonists inhabit five different areas, or “Sectors”, which replicate a specific era. In the real world 2188, a nanomachine virus ravaged the Earth, leaving only fifteen survivors; the thirteen protagonists, as well as Okino and Tamao. The survivors initiated Project Ark, sending their DNA and records of their history to a new planet where they would restart humanity. The events of the game are happening on a distant terraformed planet and the simulation housing and training their minds is otherwise populated by human-like AIs. Project Ark and its population are managed by Universal Control, an AI that erases inconsistencies and falsifies information to preserve the simulation. The 2188 Shinonome, disillusioned with humanity, secretly implemented the Deimos Code; this would cause Shikishima, a mega-corporation that exists in all Sectors, to produce the Deimos. Once the Deimos invades all five Sectors, the simulation resets to sixteen years before protecting Universal Control, with the fifteen humans losing their memories of the events, trapping them in an endless loop. Some characters survive loops with their memories intact using “Sector 0”, a non-spatial area at the system’s core.

Some key plot threads are scattered through each character’s narrative. Ida, an earlier version of Amuguchi, seeks to perpetuate the loops in an attempt to restore an earlier version of his lover Kisaragi, who exists in the current world as Inaba. He loses hope and is killed after learning that Sector 0 will be erased in the next reset. 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 about their chances, she is persuaded by Gouto to aid them. Fuyusaka is revealed to be another avatar of Morimura. Minami, Takamiya, Kisaragi, Ogata, and Miura cross paths repeatedly and end up discovering several aspects of the backstory through travels to different sectors. 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. When the Deimos arrive, the 13 pilots band together to fight them, with remote assistance from Inaba and Chihiro. The pilots fend the Deimos off long enough for Inaba to contact Universal Control and shut down the simulation, allowing the pilots, together with Okino and Tamao, to awaken from their hibernation pods in the real world. Five years later, the pilots have formed families with their loved ones on the new planet. They restore the simulation and all its inhabitants and plan to use the pods to create bodies for the AI humans so they can all live in the real world. Inaba and Ida plan to live in Universal Control, while Izumi and Morimura are reunited in the simulation. 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.