Case Study 19.2 — Hollow Knight: Hallownest and the Self-Revealing World

Game: Hollow Knight (Team Cherry, 2017) Directors: Ari Gibson, William Pellen Team size: Three people (Gibson, Pellen, producer Jack Vine) Platforms: PC, Switch, PS4, Xbox One, macOS, Linux Why it matters: Hollow Knight is one of the most acclaimed Metroidvanias ever made. It sold over 3 million copies in its first two years, built a devoted community still active nearly a decade after release, and — most relevantly for this chapter — constructed a world (Hallownest) that is widely considered a masterpiece of Metroidvania design. A three-person team built a world that rivals games made by studios ten times their size.

The Core Idea

Hollow Knight tells the story of a small, silent insect warrior descending into the ruins of Hallownest, a fallen kingdom beneath a remote town. The kingdom is corrupted by a disease called the Infection. The player's purpose is initially unclear; it is revealed gradually through exploration, environmental storytelling, and the discovery of NPCs who partially explain the kingdom's history.

Mechanically, Hollow Knight is a 2D Metroidvania: a sidescrolling action game in an interconnected world where new abilities unlock new paths. The player wields a Nail (sword), casts spells, and progressively acquires traversal abilities — Mothwing Cloak (dash), Mantis Claw (wall jump), Crystal Heart (superdash), Monarch Wings (double jump), Isma's Tear (acid immunity), Shade Cloak (dash through enemies), Kingsoul (plot), and others.

The world, Hallownest, is the game's true protagonist. It is vast (relative to the game's scope), intricately interconnected, thematically cohesive, and gradually revealed. It is arguably the finest example of Metroidvania world design in the medium.

💡 Intuition: When people remember Hollow Knight, they remember places: the fog of Greenpath, the rain of the City of Tears, the neon decay of Crystal Peak, the crushing silence of the Abyss. The mechanics and bosses are great, but the world is what haunts players. This is the mark of world design working.

The Topology of Hallownest

Hallownest is roughly hemispherical — a dome-shaped underground space beneath the surface town of Dirtmouth. It comprises many regions, each with distinct visual identity, music, and mechanical character:

• Dirtmouth. The surface town. A handful of NPCs. The game's hub-adjacent space — players return here but do not linger.
• Forgotten Crossroads. The topmost region of Hallownest proper. Crossroads layout (it lives up to its name) that connects to multiple other regions.
• Greenpath. A lush, moss-covered region full of living nature still thriving in the ruins.
• Fungal Wastes. Mushroom forests, spore pods, mycelial passages. A distinctly biological region.
• City of Tears. The former capital, now drowned under perpetual rain. Architecturally grand, emotionally melancholy.
• Crystal Peak. Vertical mines with exposed crystalline formations. Heavy machinery, neon-crystal lighting.
• Resting Grounds. A gray, somber region of tombs and the floating Seer.
• Royal Waterways. The sewers of the capital. Dark, damp, dangerous.
• Deepnest. The darkest region. Procedural-feeling (though handcrafted) twisting passages with terrifying enemies.
• Kingdom's Edge. The far eastern reaches. Sky-like; high wind; dragon imagery.
• Ancient Basin. The deep heart of Hallownest. Below the City of Tears; above the Abyss.
• Abyss. The lowest region. Primordial, void-haunted, origin of the game's central mythos.
• White Palace (and Path of Pain). Hidden dream-space. Former royal residence. Endgame platforming.

Each region has its own visual palette, music, enemy roster, environmental hazards, and narrative role. No two regions are confusable. This is the Hollow Knight mental-map foundation — massive visual differentiation produces reliable navigation.

📝 Note: The three-person team at Team Cherry achieved this world by making every region an authored artistic statement. Each region's music (composed by Christopher Larkin) reinforces its character. Each region's enemies (animated by Ari Gibson) reinforce its biology. Each region's layout (designed by William Pellen) serves its thematic purpose. This unity across disciplines is why Hallownest feels so cohesive.

The Hub Question

Hollow Knight is subtle about its hub structure. Dirtmouth is the surface town, but the player rarely uses it as a hub in the Super Mario 64 sense. Instead, the world functions through a distributed network of save points (Benches) and strategic returns to specific NPCs.

The nearest thing to a true hub is a combination of three locations: - Dirtmouth for starting-area shops, Iselda's map shop, and emotional homecoming. - Forgotten Crossroads for Cornifer (early map seller), Sly (tool shop), and as the transit hub between early regions. - City of Tears (late-game hub) for Lemm (relic trader), major story NPCs, and central location in the world topology.

This multi-hub structure means the player never returns to a single location for long. The hub role rotates based on the player's progress. Dirtmouth fades in importance once the player reaches deeper areas. The City of Tears becomes the de facto hub in the mid-game.

💡 Intuition: For a world this interconnected, a single hub would feel restrictive. The player would spend too much time returning to one location. By distributing hub functions across several locations, Hollow Knight lets the player's effective "home" shift as they progress deeper. This mirrors the fact that Hallownest is a descent — your home is wherever you have most recently reached.

The Self-Revealing Map

Hollow Knight's map system is one of the game's signature design choices. Unlike most games, where the map is always accurate and comprehensive, Hollow Knight's map is a discovered artifact that updates only when you choose to make it update.

The system works as follows:

Maps must be purchased per region. To have a map of a region at all, you must find Cornifer (a wandering cartographer whose distinctive humming audio hints at his location) and buy the map from him. If you haven't bought the map for the region you're in, you have no map at all.

Maps start incomplete. Even after you buy a region's map, it shows only the rough structure — often just a fragment of the region. The rest fills in as you explore.

Maps only update at Benches. The map does not update in real time as you explore. It only redraws when you sit on a Bench (save point). This means that during exploration, you remember where you've been — and you mentally project it onto the (outdated) map in your inventory.

You can choose to see your location. You must purchase the Compass charm to see your location on the map. Without the Compass, the map shows the region's layout but not where you currently stand.

Not all content is mapped. Secret areas, dreamgates, and certain deep regions do not appear on the map even after exploration. You remember them by note or by mental model.

This system is the opposite of modern AAA map design, which trends toward comprehensive, always-updated, icon-saturated minimaps. Hollow Knight's map demands that the player hold the world in their head. The map is a reference, not a substitute.

🚪 Threshold Concept: The Hollow Knight map forces the player to build a real mental map of Hallownest. Because the map does not give you the world for free, you must form a cognitive model of where things are. This produces deep familiarity with the world — the kind of familiarity that makes players feel like they live in Hallownest, not just visit it.

Interconnection as the Core Aesthetic

Hollow Knight's world is interconnected in the Dark Souls sense — a single coherent space, not a series of rooms. The player descends from Dirtmouth into the Forgotten Crossroads, then branches outward through the various regions, then deeper into Ancient Basin and the Abyss. All of it is one continuous world.

Specific interconnections: - Dirtmouth → Crossroads via a single well/elevator shaft. - Crossroads ↔ Greenpath via the west passage. - Crossroads ↔ Fungal Wastes via southern descent (later unlocked with acid immunity). - Greenpath ↔ Fungal Wastes via a hidden passage (after acquiring Mantis Claw). - Fungal Wastes ↔ City of Tears via an elevator and upward climb. - City of Tears ↔ Resting Grounds via upward tram (requires Simple Key). - City of Tears ↔ Royal Waterways via downward descent. - Royal Waterways ↔ Ancient Basin via deeper descent. - Ancient Basin ↔ Abyss via gated entry (requires Kingsoul). - Kingdom's Edge accessible from City of Tears and Royal Waterways. - Deepnest accessible from Fungal Wastes (one-way initially) and Distant Village.

Many of these connections are one-way on first traversal (you drop into a region from a ledge you cannot climb back up) but become two-way after ability acquisition. The player discovers over time that the world loops back on itself in ways they did not initially see.

The Stag Stations, an underground transit system, provide fast travel between discovered stations. But — crucially — each Stag Station must be unlocked on foot. You cannot fast-travel to a station you have not physically reached. This is identical to Elden Ring's Site of Grace system and produces the same effect: the world's scale is felt on first traversal, then efficient on return trips.

💡 Intuition: The interconnection of Hallownest rewards the player's memory. You remember that ledge you saw two hours ago. You now have Mantis Claw. You return. You climb. You discover the passage leads to a region you've been exploring from the opposite direction. The two regions click together in your head. This moment — the "oh, I see!" — is Hollow Knight's most repeatable pleasure.

Gating Through Abilities

Hallownest's progression is gated through eight core abilities, each of which opens new regions or dramatically expands existing ones.

Each ability is a hard lock. You cannot bypass them with skill. You cannot sequence-break to access deep content without the correct abilities. This was a deliberate choice — it keeps progression clean and ensures every player experiences the narrative in roughly the right order.

(Advanced players have discovered some soft lock bypasses — notably the Crystal Heart zip that lets skilled players reach areas "early" — but these are speedrun techniques, not intended play.)

✅ Best Practice: Each ability in Hollow Knight is both a combat upgrade (double jump helps in fights) and a traversal key (double jump opens new paths). This dual-purpose design means every ability is immediately valuable for current combat and retroactively valuable for past exploration. The player feels both stronger and more expansive after each acquisition. Design your abilities to work this way. An ability that only opens paths is less satisfying than one that also enhances moment-to-moment play.

The Bench as the Soul of the Loop

Hollow Knight's Benches are more than save points. They are the game's emotional architecture.

A Bench does several things: - Saves the game - Restores health (if you sit for a moment) - Resets all enemies in the region (they respawn when you leave the bench area) - Updates the map with any new exploration - Allows equipping/unequipping Charms (Hollow Knight's loadout system) - Functions as a moment of rest — your Knight literally sits and catches their breath

The resting animation is quiet. The music often softens. Your Knight sits with folded arms, head slightly bowed. For a moment, the world is still.

Mechanically, the Bench is essential. Charms can only be changed at Benches, which means loadout planning happens between exploration segments. This design decision — preventing loadout swapping mid-battle — keeps combat encounters committed and tactical.

Emotionally, Benches are punctuation. Long exploration stretches are broken by moments of rest. The player catches their breath. They plan. They reflect. Then they stand and continue.

🔗 Connection: This mirrors Dark Souls' Bonfire system, which serves similar functions. Both games use their rest-and-save points as deliberate emotional punctuation. The "I made it to a bonfire" moment is one of the Souls/Metroidvania genre's most reliable pleasures. Hollow Knight inherits and refines this lineage.

The Descent as Structure

Hollow Knight's world has a clear vertical structure: surface (Dirtmouth) → upper Hallownest → mid Hallownest → deep Hallownest → Abyss. The player descends.

This structure is narrative. The surface is the world of the living (the few remaining NPCs, the memory of the kingdom). The upper regions (Crossroads, Greenpath) are still recognizable kingdoms. The middle (City of Tears, Royal Waterways) is the core of the fallen civilization. The deep (Ancient Basin, Abyss) is primordial — the origin of everything, including the player.

Each step downward is a step into deeper mystery. The player learns more about the kingdom's history with each descent. The music darkens. The lighting shifts toward cold blues and blacks. The enemies become stranger.

At the bottom is the Abyss, where the game reveals its core narrative: the Vessels, the Pure Vessel, the Knight's own origin. The deepest place is the most meaningful place. The descent is the story.

💀 Design Autopsy: Many games have themes that remain external — things NPCs say, things cutscenes show. Hollow Knight's theme is structural. The act of descending is the story of Hallownest's fall. You do not need a cutscene to explain the kingdom's decay; you feel it as you move downward. This is world-as-narrative at its purest.

The Optional Content That Became Essential

Hollow Knight has several pieces of content that are technically optional but have become, in player memory, essential:

• Hornet. A recurring boss-character who pursues the Knight through Hallownest. Her appearances are scattered but feel mandatory.
• The Dreamers. Three ancient beings whose defeat is required to access the true endings. Each lives in a different region. Finding them drives much of the mid-late game.
• The Mantis Lords. A multi-phase boss fight in Mantis Village. Technically optional, but widely considered a highlight.
• The Path of Pain. A hidden platforming section in the White Palace. Entirely optional. Notoriously difficult. Completing it unlocks one line of dialogue.
• The Trial of the Fool. The hardest tier of the Colosseum of Fools. Optional. Brutal.
• Godmaster (free DLC). An entire additional endgame mode added in a free update. Optional, but extends the game by 10-20 hours for committed players.

This structure — a main spine of required content, with dense optional layers branching from it — is the Metroidvania ideal. Players on their first run complete the main path and feel satisfied. Players who come back or play slowly discover the depths. Every player builds their own relationship with Hallownest.

🎯 Tradeoff Spotlight: Hollow Knight's optional content is so rich that some players — including critics — have called for more "direction" to ensure new players find it. Team Cherry has resisted. The opacity is intentional. The reward for the player who finds the White Palace without a guide is categorically different from the reward for a player who follows a walkthrough. This is a design principle, not an accident.

The Hand-Drawn Aesthetic as World Design

Hollow Knight is famously hand-animated, with art by Ari Gibson. Every creature, every character, every background element is hand-drawn at low resolution and up-scaled.

This is relevant to world design because the aesthetic is the world. Hollow Knight could not look like another game. The characters are insects with distinctive expressive silhouettes. The environments are inked backgrounds with soft fog. The color palette is region-specific and emotionally charged. The music (also region-specific) reinforces the visual identity.

The result is that each region feels like a page from an illustrated storybook. This is rare in games. Most games achieve visual differentiation through lighting or color grading. Hollow Knight achieves it through the underlying artwork itself.

For you, the practitioner, the lesson is: your world's visual language is itself a design decision. If your engine renders all regions with the same lighting, same texture style, same color profile, your world will blur together regardless of layout. Visual differentiation at the aesthetic level — lighting, color, art style, sound — multiplies the differentiation you build into layout.

📝 Note: Hollow Knight's three-person team could not compete with AAA studios on scope or polish. They competed on artistic voice. The result is a world with more personality than games with ten times the budget. Small teams: lean on voice. Your handcrafted specificity is the thing a large team cannot easily replicate.

Lessons for Your World Design

1. Interconnection creates cognitive unity. A world that loops back on itself feels like a place, not a gallery.
2. Visual differentiation is mental-map fuel. Make each region unmistakable.
3. The map should be earned. Purchased, explored, updated only at rest points — a discovered artifact, not a given.
4. Hard-lock your ability gates for progression clarity. Let soft locks emerge for advanced play.
5. Distribute hub functions. A single hub feels like a traffic jam. Multiple location-based hubs let the player's "home" shift with progression.
6. Make abilities serve traversal AND combat. Dual-purpose abilities feel more rewarding than single-purpose ones.
7. The descent is narrative. Your world's physical structure can carry thematic weight. Use it.
8. Hidden content rewards curiosity. Not everything should be signposted. Some of your best content should require the player to look.
9. Rest points are emotional architecture. Benches, bonfires, sites of grace — design them as moments of reflection, not just save points.

Conclusion

Hollow Knight is proof that world design is not a function of team size or budget. Three people, working for years, built a world that rivals the largest studios' largest games. The world is unified, interconnected, visually distinct, narratively layered, and genuinely memorable.

What Team Cherry demonstrated is that world design is a function of artistic intention and careful iteration. Every region of Hallownest was designed deliberately — its layout, its music, its enemies, its role in the broader world. Nothing is there by accident. Nothing is filler.

When you design your world, approach it the way Team Cherry did. Not as a map to fill with content, but as a place to construct with meaning. Each region is a chapter. Each passage is a sentence. The whole is a story told in geography.

Hallownest is a fallen kingdom. In playing Hollow Knight, you inherit it for a while. When you leave, the place stays with you. That is what a world, designed well, does: it does not simulate a place; it gives you one.

Go design a place worth inheriting.