Operation Ninurta - Eris Portal
Release date: Jun 26, 2025
Developers: Mariani Games
Publishers: Mariani Games
Genres: Action, Adventure, Casual, Indie
Categories: Single-player, Steam Achievements, Camera Comfort, Custom Volume Controls, Adjustable Difficulty, Stereo Sound, Surround Sound, Family Sharing
Supported languages: English, French, Italian, German, Spanish - Spain, Simplified Chinese, Traditional Chinese, Korean, Japanese, Polish, Portuguese - Brazil, Russian, Turkish

Operation Ninurta – Eris Portal Operation Ninurta – Eris Portal is a third-person tactical shooter with roguelike elements, set in the near future, where Earth soldiers are sent on solitary missions through spatial portals. You are the next to cross... Your destination: Eris, a dark planetoid on the edge of the Solar System, marked by signs of alien presence and structures that defy the known laws of physics. Origin of the Operation The operation was created by LEAP — Laboratory for Advanced Portal Studies — after the discovery of archaeological artifacts containing coordinates to ancient portals hidden among celestial bodies. However, current technology allows only one traveler to cross every 40 hours. This limitation led to the formation of a special unit: elite soldiers trained for solitary missions in unknown territories. Mission Your mission is clear: investigate Eris, find three crystal keys that power the portal structure, and use them to reactivate the connection back to Earth. But the task quickly proves more dangerous than anyone expected. The planetoid holds a maze of interconnected hexagonal rooms — a system that, at first glance, seems to obey the rules of three-dimensional space. Hexadimensional Reality However, as you pass through these doors, you soon realize something is wrong. The topology of the maze follows a logic based on the six-faced hypercube theory, where time is treated as a physical dimension. This means entering a room through one door and trying to return through it won’t take you back to where you came from. Each movement alters space in unpredictable ways. There is no easy return. Moving forward is your only choice. Dangers While exploring the facility and searching for the keys, you'll face mutant creatures — life forms genetically manipulated by ancient alien civilizations. These unarmed enemies pose no direct threat, but they move in groups, act erratically, and are used to distract your attention. Their role is simple and cruel: create chaos and open space for the real danger. Aliens Armed enemies appear randomly as you progress. They are lethal, and both their presence and quantity are carefully controlled by a system of increasing difficulty. Every 20 levels, a new Boss enters the scene — each with their own abilities and combat style. Defeating a Boss is not just a matter of survival: it unlocks new enemies that are added to future spawn calculations, making each run more challenging than the last. Strategy The game’s structure was designed to emphasize strategic decision-making. The player starts with limited ammunition, and every shot must be calculated. Excessive firing can leave you defenseless even in the early rooms. But there is a way to adapt: when you die, your score is preserved and can be used to acquire extra magazines for the next mission. Over time, you'll learn to conserve resources, anticipate patterns, and survive deeper into the maze. Random Procedural World Even so, time remains your greatest enemy. The longer you stay on Eris, the more unstable your presence becomes. Returning grows increasingly uncertain. Each attempt is a struggle against creatures, the environment, scarcity, and the very structure of reality. There is no fixed map. No known path. Every player will have their own journey. Game Duration On Eris, there are only two ways for the game to end: either you die, or you manage to find the return portal, activate it, and make it back to Earth. How long will that take? It’s up to you. As long as you’re alive, Eris will try to crush you — until you finally succumb. It may last hours... or days in this agony.