Emissary Zero, a cooperative horror experience, has garnered over 1,700 reviews on Steam with an impressive 82% positivity rate. With more than 150,000 copies sold, this title has exceeded the expectations of its solo creator, who describes the development journey as a series of frantic, miraculous achievements. In a detailed Reddit post, indie developer Rone Vine shares the story behind creating “a horror game that accidentally sold 150k copies.” Initially envisioned as a linear horror game with optional multiplayer elements, Emissary Zero drew inspiration from Five Nights at Freddy’s, incorporating aspects such as surveillance cameras, dynamic challenges, and roaming monsters. Ultimately, it evolved into a “walking simulator” featuring environmental interactions and puzzles, allowing players to explore a haunting, monster-riddled building solo or with up to three friends.
Development Journey and Initial Goals
Vine’s prior project, a Soulslike game called Estencel, took a considerable amount of time to complete. After leaving a freelance position in early 2024 to dedicate their efforts to Emissary Zero, Vine aimed to create a product that could be finished relatively quickly. They noted, “Even if this one failed, at least it wouldn’t take forever.”
When discussing the game’s development, Vine acknowledged their resource constraints as a solo developer. In subsequent Reddit replies, they stated, “Of course I used a lot of assets.” However, they expressed a preference for remaining a solo developer without plans to expand their team or establish a studio, as their game development skills are largely self-taught, following a year spent in a college technical program.
The Launch Experience
Emissary Zero officially launched on March 28, 2025. Vine revealed in a Reddit response, “I was running out of money,” and that launching in March ensured a May payday. They faced financial insecurity, stating, “I had no other money left at all” when the first earnings were received. With its release date set as of January, Vine mentioned, “delays were no longer possible.” They described the last three months as a period of intense crunch, detailing that just three weeks before the launch, Steam rejected the build due to copyright concerns involving a character resembling Slenderman. Fortunately, this issue was resolved just two days prior to release.
Vine recounted, “Communication with support and approving the build took a while, but thankfully, it was resolved.”
Overcoming Launch Challenges
The hurdles didn’t end there. Vine noted that the storyline was finalized merely “two weeks before launch,” and the actual game texts were completed just “three days before release,” utilizing machine translation for other languages. “It worked surprisingly well – I haven’t seen any Steam reviews complaining about translation quality,” Vine added.
Despite the stresses of release, they noted there was minimal marketing—a few unsuccessful attempts on Twitter. The launch itself was relatively subdued, with “Mixed” reviews highlighting optimization and difficulty issues, which Vine quickly worked to address through hotfixes.
Post-Launch Success
After an initial steady start, Vine observed that sales began to increase significantly in April, driven by a viral TikTok video that brought the game to a wider audience. By October 5, Emissary Zero had sold over 150,000 copies, and Vine is now focused on developing a sequel, incorporating fresh ideas that will build on the mechanics established in this first installment. “I’d also love to bring it to consoles this time,” they shared.
Reflecting on the overall journey, Vine concluded, “This game was a unique experience. It started as a small project but ended up exceeding all expectations. For me, that’s a success.”