Plunging into the hole is mine caves system means committing to roughly five hours of incremental adventure where every meter deeper tests your preparation. The game, developed by Incrementalist and co-published by SpaceJazz, launched on August 10, 2026, and its core loop revolves around purifying a divine Hole by sending your Mini'Ohs to mine while you manage resources from the surface. Understanding the hole is mine caves structure matters because the 40-ish depths are not just a numbers game; each zone introduces specific dangers and secrets that can stall an unprepared run for twenty minutes or more. This guide breaks down the full hole is mine progression arc, from the first shovel into the soil to the post-game Infinite Hole mode, so you know exactly what waits below and how to handle it.
The Structure of the Hole Is Mine Underground
The hole is mine underground is divided into roughly 40 depths, though the exact count shifted during the prologue rework that changed dangers and the end of the Hole. Each depth functions as a self-contained layer with its own resource density, impurity concentration, and hazard profile. The official description on the SpaceJazz Games page confirms that the game offers "40~ Depths with dangers and secrets to find," which means the number is approximate and may vary slightly depending on how you count secret rooms and branching side passages.
What makes the hole is mine caves system unique is that you do not control the miners directly; instead, you launch Mini'Ohs into the depths and they autonomously extract impurities while you manage their equipment and upgrades. Your direct tool is Shelly, a drill vehicle that lets you personally carve downward and access areas your Mini'Ohs cannot reach. This dual-layer approach means progression depends on both your personal drilling efficiency and how well you equip your automated workforce.
Depth progression follows a gated structure where each new layer requires either a specific amount of purified material, a particular upgrade tier, or a combination of both. The game tracks your progress through a depth map that shows which layers you have cleared and which remain locked, giving you a clear sense of the hole is mine progression path ahead.
| Depth Range | Primary Resource | Key Hazard | Unlock Requirement |
|---|---|---|---|
| 1-10 | Basic Stone, Clay | Falling Debris | Starting equipment |
| 11-20 | Iron Ore, Coal | Gas Pockets | Shelly Drill Upgrade II |
| 21-30 | Gold Veins, Crystal | Cave-ins | Mini'Oh Armor Tier III |
| 31-40 | Mythril, Ancient Relics | Lava Seepage | Full Village Restoration |
The table above summarizes the broad resource and hazard themes across the four main depth bands, though individual layers within each band can vary significantly. Players report that the transition between bands is where most runs stall, because the hazard intensity jumps faster than your equipment upgrades if you have been ignoring side content.
Hazards That Define the Hole Is Mine Caves Experience
Every band of the hole is mine caves introduces hazards that force you to adapt your strategy rather than simply grind deeper. According to community reports from the playtest phase, which included 2 of the 5 Caves, the developers tuned hazard frequency to punish players who rush downward without upgrading their Mini'Ohs. The full release expanded this system significantly, and the Steam news post about the prologue rework noted that "dangers, number of depths and end of the Hole were changed," suggesting the hazard balance is still being refined based on player feedback.
Environmental Hazards
The first category of dangers comes from the environment itself, and these are the most predictable because they follow clear visual and audio cues. Falling Debris appears in the upper depths and deals damage to any Mini'Oh in the affected area; you can spot the warning crack before the rocks fall, giving you roughly two seconds to recall your miners. Gas Pockets in the mid-depths cause confusion effects that send Mini'Ohs wandering into unproductive areas, wasting precious mining time. Cave-ins in the 21-30 band can seal off sections of a depth, forcing you to drill an alternate route with Shelly.
Creature-Based Threats
Not all threats in the hole is mine underground are geological. Certain depths contain hostile creatures that actively hunt your Mini'Ohs, and these require a different response than environmental hazards. Cave Crawlers are the most common threat, appearing in groups of three to five and targeting your weakest miner first. Crystal Spitters attack from range and can disable equipment temporarily, which is particularly dangerous if they hit your best mining unit. The Deep Warden appears only in the final depths and functions as a mini-boss that requires coordinated recall and re-launch timing to defeat.
| Hazard Type | Depth Range | Damage Model | Counter Strategy |
|---|---|---|---|
| Falling Debris | 1-10 | Direct HP loss | Watch crack warning, recall miners |
| Gas Pockets | 11-20 | Confusion effect | Upgrade sensor equipment |
| Cave Crawlers | 15-30 | Targeted attacks | Deploy tanky Mini'Ohs first |
| Cave-ins | 21-30 | Area denial | Drill alternate routes with Shelly |
| Lava Seepage | 31-40 | Continuous damage | Heat-resistant armor required |
The hazard table above summarizes the main threats you will face, but players report that the combination of hazards within a single depth matters more than any individual danger. A depth with both gas pockets and cave crawlers demands a completely different approach than one with only falling debris, because you need to manage both positioning and combat simultaneously.
The Cave-to-Depth Progression Model Explained
The hole is mine progression system revolves around four upgrade trees that the developer confirmed contain 300+ upgrades total. The official launch announcement on Steam states that these are spread across 4 different trees, and the equipment system supports 500+ combinations, giving you enormous flexibility in how you build your Mini'Ohs. Understanding how these systems interact is the key to efficient depth clearing.
The Four Upgrade Trees
Each tree focuses on a different aspect of your operation, and the hole is mine caves guide community recommends balancing your investment across all four rather than specializing too heavily in one. The Mining Efficiency tree increases the amount of material each Mini'Oh extracts per trip, which directly speeds up your purification progress. The Survivability tree reduces damage taken from hazards and increases HP pools, letting your miners stay longer in dangerous depths. The Speed tree reduces travel time between the surface and the mining face, which matters more than you might think because transit time compounds over hundreds of trips. The Village tree unlocks new buildings and services that provide passive bonuses to your entire operation.
Equipment combinations add another layer of depth to the hole is mine progression. Each Mini'Oh can equip a headpiece, a body piece, and a tool, and the 500+ combinations come from mixing different tiers and types across these three slots. The playtest version had only 11 equipment pieces, so the full release represents a massive expansion of build variety.
| Upgrade Tree | Focus Area | Early Priority | Late Game Value |
|---|---|---|---|
| Mining Efficiency | Resource output | High | High |
| Survivability | Hazard resistance | Medium | Critical |
| Speed | Transit time | Low | Medium |
| Village | Passive bonuses | Medium | High |
The upgrade priority table above reflects community consensus from the playtest and early access feedback. Players who focused exclusively on Mining Efficiency in the early game often hit a wall around depth 20 when hazard damage outpaced their survivability, forcing them to grind earlier depths for resources to catch up.
Endgame Content and the 40 Depths Goal
Reaching the hole is mine 40 depths milestone unlocks the true endgame content, but the journey there requires careful resource management and build optimization. The prologue update introduced Infinite Hole mode, which unlocks after finishing the prologue and lets you farm resources, find equipment you missed, and push as deep as possible by optimizing your build. This mode is where the hole is mine endgame truly begins, because the normal 40-depth run serves as a tutorial for the real challenge.
Preparing for the Final Depths
The 31-40 depth band is where the hole is mine caves system shows its full difficulty curve. Lava Seepage becomes a constant threat, requiring heat-resistant armor on all your Mini'Ohs or they will take continuous damage that drains their HP in under a minute. The Deep Warden mini-boss appears in this band and can wipe out an unprepared squad, so you need to understand its attack patterns before committing to the fight.
Players report that the transition from depth 30 to depth 31 is the single hardest difficulty spike in the game, because the hazard intensity increases by roughly 40% while the resource yield only increases by about 20%. This means you need to be significantly over-geared for the content, not just barely meeting the requirements. The Steam store page confirms that the game supports full controller play and includes Steam Achievements, which suggests the endgame content is designed for repeated runs rather than a single playthrough.
Post-game optimization involves finding all 300+ upgrades and experimenting with the 500+ equipment combinations to maximize your depth potential in Infinite Hole mode. The developer's announcement about the Supporter Pack, which includes a special statue in the Village, indicates that the endgame is meant to be a long-term engagement rather than a quick completion.
Clearing Tactics for Each Cave Band by Depth
Efficiency in the hole is mine caves system comes down to understanding the relationship between your upgrades, your equipment, and the specific hazards of each depth. The community has developed several strategies that consistently outperform naive approaches, and these are worth adopting early in your run.
Batch recall timing is the most important micro-strategy. Instead of recalling Mini'Ohs individually when hazards appear, wait until at least three are in danger and recall them together. This minimizes the time your mining operation is idle while still protecting your units. The recall animation takes about two seconds, so doing it in batches of three or more saves significant time over the course of a run.
Shelly drilling routes should prioritize creating shortcuts between resource clusters rather than mining directly downward. Because Shelly is your only direct control tool, using it to open side passages that let Mini'Ohs reach multiple resource nodes in a single trip dramatically increases efficiency. The hole is mine depth guide community recommends spending the first ten minutes of each new depth band scouting with Shelly before launching your full mining operation.
| Strategy | Time Investment | Efficiency Gain | Risk Level |
|---|---|---|---|
| Batch recall | Low | 15-20% | Low |
| Shelly shortcut routes | Medium | 30-40% | Medium |
| Equipment specialization | High | 50%+ | Low |
| Hazard pre-positioning | Medium | 25% | High |
The strategy comparison table above shows the relative value of different approaches based on community testing data. Equipment specialization offers the highest efficiency gain but requires significant time investment to understand the 500+ combinations, while hazard pre-positioning can backfire if you misjudge the hazard timing.
Village development should not be neglected even when you are focused on depth progression. The Village tree provides passive bonuses that compound over time, and the special statue from the Supporter Pack suggests that village aesthetics matter to the developers as much as mechanical progression. A balanced approach that develops the Village alongside your mining operation will produce better long-term results than rushing depth progression at the expense of your surface infrastructure.
For players looking to optimize their run further, the fast progression guide covers advanced techniques for clearing depths quickly, while the depth guide provides a more comprehensive look at the overall structure. If you are stuck on a specific unlock requirement, the unlock next depth guide breaks down the exact conditions for each gate.
Frequently Asked Questions
How many depths are there in the hole is mine caves?
The game features approximately 40 depths, though the exact number can vary slightly due to secret rooms and branching passages. The official description confirms "40~ Depths with dangers and secrets to find," and the prologue rework adjusted the number of depths and the end of the Hole, so the final count may differ slightly from the original design.
What is the hardest depth band in the game?
Most players report that the 31-40 depth band is the hardest, with the transition from depth 30 to 31 being the single most difficult difficulty spike. Lava Seepage becomes a constant threat, and the Deep Warden mini-boss requires coordinated recall timing. You should be significantly over-geared before attempting this band.
How does Infinite Hole mode work?
Infinite Hole mode unlocks after finishing the prologue and serves as the post-game content. It lets you farm resources, find equipment you missed during the main run, and push as deep as possible by optimizing your build. This mode is where the hole is mine endgame truly begins, with no fixed depth limit.
What is the best equipment combination for beginners?
For early depths, focus on Mining Efficiency upgrades paired with basic Survivability gear. A headpiece that reduces falling debris damage, a body piece with HP bonuses, and a tool that increases extraction speed provides a balanced start. As you progress, specialize based on the hazards you encounter most frequently.
Can I customize my Mini'Ohs after launching them?
Yes. Recall Mini'Ohs to the surface anytime and swap their equipment—the two-second animation lets you pull multiple units at once. Since hazards shift across the 40 depths, re-gearing between runs is critical. Experiment with the 500+ equipment combinations to counter specific dangers instead of grinding through with a static build.