Time-Travel Tactics RPG Gets Atomic Heart Crossover

Mundfish probably wasn't expecting Atomic Heart to produce this many spin-offs when it released the retrofuturistic shooter in 2023, but what seemed even less likely then was a seamless crossover with a turn-based tactics RPG.

As revealed in a livestream today by Bluepoch, Atomic Heart is launching an in-game collaboration with Reverse: 1999, a free RPG based on a world where time started going backwards in 1999.

The Atomic Heart event is set to kick off on July 23, marking the first time that both the international and Chinese versions of Reverse: 1999 will be synchronized.

Wizards, Twins, and Time-Travel

Apart from the creative take on the Year 2000 problem, Reverse: 1999 is introducing some of the more iconic elements from Atomic Heart into this new chapter.

The story will take the characters from Reverse: 1999 into the depths of Atomic Heart's Facility 3826. It is also expected to feature new narratives for Atomic Heart regulars, especially The Twins robots and NORA, the repair cabinet that is the main antagonist of the Annihilation Instinct DLC, which launched the same year as the base game.

Apart from narrative additions, The Twins will be available as summons, featuring their own banner and reward system. The robotic bodyguards will be the first characters in Reverse: 1999 able to inflict damage across two Aflattus types. True to their twin nature, they will also be capable of dual-wielding Psychubes, giving them two full sets of base stats.

Meanwhile, a four-star NORA can be recruited as part of gameplay progression, pairing well with a free monthly pass.

In case you are new to Reverse: 1999, or want a head start in the new update, you can enter the code AtomicHeartCollab0723 for a set of rewards. To redeem it, head to the Settings menu, select Account, then click Redeem and punch it in. The bonuses will be added to your account automatically.

The Ever-Expanding Atomic Heartverse

While Reverse: 1999 is the latest Atomic Heart collaboration, Mundfish has not been shy about crossovers involving its flagship title. The game has made appearances in 4X strategy title Revival: Colonization, flight sim lite War Thunder, tactical shooter Battle Teams 2, and even a WW2 first-person shooter, World War Heroes.

These crossovers have the obvious marketing value of showcasing Atomic Heart to new audiences, but I need to give credit where it is due to Mundfish for creating a game with such a distinct aesthetic identity despite being heavily based on Soviet futurism. The success of Atomic Heart has also allowed the developer to expand on the universe in-house.

During the 2026 Summer Game Fest, Mundfish announced it was working on a sequel to its pride and joy, aptly titled Atomic Heart 2. The new chapter sees the events of the first game expand to a global scale. There is no concrete release date for it yet, but the official release window is still set for 2026. Tick tock, Mundfish.

Beyond that, the developer is also working on multiplayer RPG shooter The CUBE. As you may have surmised from the name, it is centered around a giant cube that spawned in the sky. The CUBE is part of the Atomic Heart universe, but it is unclear exactly how it fits into the original world. Then again, stranger things have happened.

Mundfish has been cagier around The CUBE, with no clear release window or even platform information besides the fact that it is confirmed to be on Steam.

Whether it will take months or years to come is anyone's guess, but in the meantime, we can speculate on what Atomic Heart's next unexpected collaboration will be.

Reverse: 1999 is available for PC, iOS, Android, and HarmonyOS. The Atomic Heart crossover event launches globally on July 23.