Inferno is an indie sci-fi horror/suspense action game and third-party spiritual successor to Descent and Descent II developed by Parallax Software. Like its predecessors, Inferno pits the player against swarms of mining robots-turned-killing machines in labyrinthine zero-gravity environments harmonizing with "six degrees of freedom" (6DoF) gameplay to induce feelings of vertigo and sensory overload. Not a clone or an innovation, Inferno advances an ideology which initiated the genre but has since been lost to copies of copies, genre-blenders, and projects that suspend it in a culture of obsessive innovation at the cost of imaginativeness. Unlike other Descent-inspired projects, it deprioritizes resource-heavy graphics and visual level-of-detail, interface features, and other "bloat", focusing instead on seizing upon the spiritual core of 6DoF gameplay. It is a radical renewal of 6DoF that pushes its core mantras--vertiginous spaces and unrelenting demand for spatial/motor coordination, simulataneous feelings of unrestraint and entrapment, vicissitudinous and tactically-intense action, etc.--beyond Descent/II to explore their practical limits. This is realized largely through level design, which aims at uninhibited maximization of spatial non-orientationality and parallactic perplexity while avoiding the compromises that made Descent/II more merciful (see Section VI) and incorporating radical non-linearity to extend gameplay into the emergent dimension. But equally crucial, it adds a vertiginous dimension to virtually every aspect of design: a punishing physics system that slightly exaggerates ballistic combat; an intelligent, cooperative A.I. system that makes combat highly variable and resistant to mastery; an inventive arsenal that includes weapons that carry a learning curve and can be counter-productive if misused; dramatic contrasts and rapid changes in light and sound; etc. Even the plot, intoned with moral vertigo, has a vertiginous quality. The effect is a dizzying psychedelia of 6DoF par excellence.

Inferno's gameplay is not immersive, but submersive. The obsessive push toward realism in game design has meant that games are progressively less real--losing the imaginative substance of gameplay to the banality of virtual reality--as they become more immersive as simulations, less distinguishable from reality. Absorption within virtually-real images, augmented to the point of hyperreality by excess, replaces inventive gameplay as the primary function of games. In effect, gameplay has scarcely appropriated the expansion of computing potential of over a decade, which has instead been accorded to the Hollywood anti-philosophy of resource-hungry immersion and spectacle and the regressive recycling of substance (gameplay). By founding itself on stylistic minimalism, Inferno places gameplay into abject focus. It is not a graphical update of Descent/II. Graphically powered by the Descent engine, it retains the mid-nineties "polygon hell" look of Descent/II in authenticity. There is no texture filtering, no partial alpha, no pixel-level shading, no "improvement" (as it is called) to the rendering engine whatsoever. But if Inferno attempts to pay homage to a "retro" aesthetic, it is only as a highly accessory priority. More importantly, it treats the graphic sparsity of the Descent/II engine as an ideal upon which to bolster the mental challenges of gameplay, rather than compensate for lack thereof. Every design element of Inferno--visual, auditory, simulatory, physical, or otherwise--compounds upon the challenge, which isn't just a tactical challenge, but a challenge to the senses as well. The player is submerged in the moment and predicament, subjected to extreme fluxes of paranoia and emergency, and offered no distractions. The modern computing power that would otherwise be wasted on visual spectacle is instead harnessed to potentiate emergent gameplay at boundary-pushing levels (via the A.I.'s cooperative behavioral relations, the paroxysm-inciting interreative physics, complex networks of level-state-dependency relations, etc.) Levels are designed to enable rather than restrict emergent gameplay, i.e. non-linear and multifaceted, often built around macroscalar schemes with central hubs and arena-style interconnectivity, dauntingly complex yet organic and coherent, not frustrating to navigate. All of the mentioned design complexities accomodate the fluidity of rather than complicate gameplay, the premise of which remains consistent throughout, not riddled with arbitrary objectives and side-tasks.

Inferno is potentially far more challenging than its predecessors, thus far more replayable. It weeds out the weaknesses which allowed relatively easy mastery of 'insane' difficulty level in Descent/II, including the cumulative lives system and the near-ubiquity of save-game opportunities. Though save-game functionality is identical to that of Descent/II, levels are designed so that the player often finds himself in predicaments demanding his uninterrupted focus and unfaltering performance for long periods, implicitly limiting game-save opportunities. Selective confrontation and route planning are of far greater importance in Inferno--so much so that some combat scenarios, under certain level-state conditions, are impossible to win on higher difficulty levels. A fatal decision in this regard, or in e.g. resource management, might render several game saves unusable. Though gameplay style and premise remain consistent to Descent/II standards, the player finds it necessary to adapt to an evolving set of limitations and opportunities. Familiar enemies may suddenly exhibit new defensive tactics, occurrences of which are not easily anticipated even upon repeated plays. Certain weapons may carry greater use-risk and/or exhibit more unpredicatable behaviors in certain environmental or combat conditions. (Examples of the forementioned are found in later sections.) But it should be reiterated that tactical variability is merely one of a full spectrum of design elements that puts Inferno on the fringes of challengingness, a spectrum that synergizes into a submersive reality that is the feelings of shock, suspense, chaos, sensory overload, and vertigo, not an immersive virtual reality of simulated images that fails to stimulate real emotions.