Ion Fury does something no other game in the retro FPS revival attempts: it actually runs on the Build engine, the same technology that powered Duke Nukem 3D and Shadow Warrior in the 1990s. Developed by Voidpoint and published by 3D Realms in 2019, the game pushes the classic engine to its absolute limits, delivering a cyberpunk FPS that looks and plays like a lost classic from 1997 while incorporating modern design sensibility. You play as Shelly “Bombshell” Harrison, a bomb disposal specialist turned action hero fighting through a cybernetic army in a neon-soaked city.
Player reception has been strongly positive, with particular praise for the level design and the technical achievement of building a modern game on decades-old technology. The Build engine heritage gives Ion Fury a specific visual character, detailed 2D sprites in richly interactive 3D environments, that other retro shooters emulate but can’t truly replicate. Criticism tends to focus on the protagonist’s one-liner delivery, which aims for Duke Nukem’s swagger without consistently hitting it, and on the game’s conservative approach to the genre, preferring faithful recreation over innovation.
Build Engine Mastery in Neon
The level design is Ion Fury’s greatest strength and the element that best justifies the Build engine choice. Maps are sprawling, dense, and layered with interconnected paths, hidden rooms, and environmental details that reward exploration. Decades of Build engine mapping knowledge inform the design, and the result is levels that feel hand-crafted in a way that modern tools sometimes obscure. Every room has a purpose. Every corridor leads somewhere meaningful. The density of secrets hidden in the environments rivals the best of Duke 3D, and finding them is consistently rewarding.
The weapon roster delivers satisfying options across all engagement ranges. The Loverboy revolver serves as a reliable sidearm with an alternate fire mode that locks onto nearby targets. The Disperser shotgun provides the close-range punch the genre demands. The Penetrator submachine gun handles crowd control, and the bowling bombs create explosive chaos. Each weapon has alternate fire modes that effectively double the arsenal, and the variety ensures you’re constantly rotating based on the encounter.
The cyberpunk setting gives the Build engine aesthetic a visual identity distinct from the games that inspired it. Neon signs, holographic displays, and industrial corridors replace the movie-set levels of Duke 3D, and the consistency of the visual theme creates a world that feels cohesive rather than episodic. Environmental interactivity, a hallmark of Build engine games, is present throughout, with destructible objects, interactive machines, and hidden switches scattered across every level.
Faithful to a Fault
Ion Fury’s commitment to authenticity means it inherits some limitations along with the strengths. The movement speed and level design follow Build engine conventions faithfully, which means players accustomed to the faster, more aerial movement of modern retro shooters like Dusk or Ultrakill may find Ion Fury slower and more grounded. The game doesn’t offer movement options beyond running and jumping, and some encounters in the late game drag without the variety that additional mobility would provide.
Shelly’s one-liners are hit-or-miss. The game clearly wants its protagonist to fill the Duke Nukem role of quipping action hero, but the writing doesn’t consistently achieve the right balance of confidence and humor. Some lines land well. Others feel forced or flat. The inconsistency means the character never fully establishes the personality the game wants her to have, though this is a minor complaint given how little time you spend listening versus shooting.
The length, while generous for the genre at roughly twelve to fifteen hours, means some sections overstay their welcome. The final episodes could benefit from tighter pacing, as the level design, while consistently good, doesn’t escalate enough to justify the runtime. Some late-game levels repeat encounter structures that were introduced hours earlier, creating a sense of formula that the inventive early levels avoid.
The Real Thing
Ion Fury’s use of the actual Build engine isn’t just a technical curiosity, it’s a design philosophy. The limitations of the engine constrain the game in ways that produce specific design qualities. The 2D sprite enemies, the sector-based level geometry, the software-rendered lighting, these aren’t nostalgic choices made from a palette of modern options. They’re the tools the developers had to work with, and the creativity forced by those constraints produces results that intentional recreation can’t duplicate. Ion Fury doesn’t look like a Build engine game. It is a Build engine game, and that distinction matters.
The Afterburner expansion, released in 2021, added several additional levels that match the quality of the base campaign, extending the experience for players who wanted more.
Should You Play Ion Fury?
If you have fond memories of Duke Nukem 3D, Shadow Warrior, or Blood and want a modern game that captures that exact feeling, Ion Fury is the closest you’ll get. Level design enthusiasts who appreciate dense, secret-filled maps will find some of the best examples in the genre here. Anyone interested in the technical achievement of a modern game running on 1990s technology should experience it firsthand.
Pass if the Build engine aesthetic, with its 2D sprites and sector-based geometry, doesn’t appeal to you. Players who prefer the faster movement and more dynamic combat of newer retro shooters will find Ion Fury relatively restrained. If one-liner protagonists in FPS games annoy you regardless of quality, the constant quipping may wear thin.
The Verdict on Ion Fury
Ion Fury is the most authentic retro FPS experience you can get in the modern era, built on the actual Build engine that powered Duke Nukem 3D. The level design is dense with secrets and interconnected paths, the weapons are satisfying, and the cyberpunk aesthetic gives the classic formula a fresh coat of neon paint. It lacks the mechanical innovation of some peers and the protagonist’s quips don’t always land, but as a pure throwback to the golden age of Build engine shooters, it’s exceptional.