Gravedigger.io – The Night Shift: Complete Strategy Guide

Overview

Gravedigger.io – The Night Shift is a single-file, zero-dependency first-person zombie wave-defense game that runs entirely in your browser. Developer eons2eons packed the whole game, procedural graveyard, six-weapon arsenal, escalating waves, synthesized audio, HUD, into one index.html file built on Three.js r128. No install, no build step, no asset downloads. The only external resource is the Three.js CDN script tag.

You are the gravedigger on the night shift. The dead refuse to stay buried. Zombies claw out of the ground across a procedural graveyard, and your job is to hold the line as long as you can. There is no final wave. The horde doubles forever, and the run ends when you fall.

Where to play: The itch.io page is author-restricted as of August 2026, so the reliable link is the GitHub Pages build, which serves the identical game file:

https://eonstoeons.github.io/Gravedigger.io-The-Night-Shift/

You can also clone eonstoeons/Gravedigger.io-The-Night-Shift and open index.html locally. Any modern desktop browser with hardware acceleration works: Chrome, Firefox, Edge, Safari.

Why it stands out: the entire game was generated from a single AI prompt, then lightly polished. That makes it a fascinating case study in AI game dev and a genuinely tense wave shooter. The source is MIT-licensed for modding, though the game's design and branding stay All Rights Reserved.

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Getting Started: Your First Shift

Launch Checklist

1. Open the GitHub Pages URL (or local index.html) in a desktop browser.
2. Confirm WebGL works. If the screen stays black, enable hardware acceleration in browser settings.
3. Click BEGIN THE SHIFT.
4. You get a 0.6-second grace period before wave 1. Use it to scan the graveyard for glowing pickups.

First Run Goals

• Wave 1 is a tutorial in disguise: 5 slow zombies, shovel only.
• Locate the pistol pickup (it spawns in the ring 10–63 units from the center) and grab it.
• Mark ammo crate positions. Ten crates spawn each run, each refilling every gun you carry.
• Survive wave 1, then use the 4.2-second break to grab the shotgun or SMG.

Beginner Mistakes

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Core Mechanics

Health & Regeneration

• Max HP: 100. Each zombie hit deals 20, so you die in exactly 5 hits.
• Regen trigger: 4.2 seconds without taking damage.
• Regen rate: 4 HP per second. From 40 HP to full takes about 15 seconds.
• Hit feedback: red flash (0.35s) + camera shake.
• Low HP warning: below 30 HP, a pulsing red vignette and heartbeat audio kick in (1.6Hz timer).
• HUD regen text: "wound fresh, regen delayed" while the timer counts, then "recovering…". This is the game's own HUD wording, kept verbatim.

The regen delay is your biggest tactical constraint. When hit, disengage for at least 4.2 seconds. Kite zombies into a line, break line of sight behind the mausoleum or trees, and only re-engage after the heal starts.

Wave Scaling

Wave total  = 5 × 2^(wave − 1)
Concurrent  = min(20, 5 + wave × 2)
Spawn delay = max(0.22, 0.95 − wave × 0.03) seconds × random(0.7–1.3)

The concurrent cap means zombies queue and spawn as you kill. You never face all 640 at once at wave 8, but you must kill every single one to clear the wave, and the queue refills in under a second at high waves.

Zombie Behavior

Each zombie runs a four-state machine:

1. Rising: 1.65 seconds to emerge from the ground. Untargetable, harmless.
2. Chasing: paths to you at 1.35–2.5 units/second, with separation AI and mild tombstone avoidance.
3. Attacking: lunges within 1.55 units, deals 20 damage, then cools down for 1.05 seconds.
4. Dying: sinks into the ground over 0.9 seconds.

Because attack cooldown is over a second, a single zombie is nearly harmless; you can walk through its swing. The danger is always numbers. Zombies separate from each other within 0.85 units, so they spread into a crescent instead of stacking. Expect flanking, never a single-file line unless the terrain funnels them.

Weapon System

Key math:

• Shovel: kills any zombie in one swing inside a 54° frontal cone within 2.55 units. Zero ammo cost. It stays useful forever as a finisher and ammo saver.
• Assault rifle: 4 shots per zombie (28 × 4 = 112). 30-round mag = 7 kills per mag, ~255 DPS at any range up to 72 units. Your main weapon from wave 5.
• Shotgun: all 8 pellets landing deals 152, one blast per zombie at close range. Under 12 units it dominates; past 24 units it whiffs.
• Gatling: 440 DPS, 100 rounds = 5 seconds of continuous fire, then a 2.6-second reload where you cannot shoot. Treat it as a panic button, not a primary.

Ammo Economy

• Five gun pickups (pistol, shotgun, SMG, rifle, gatling) spawn once per run, 10–63 units from center. Each arrives fully loaded. Miss one and it's gone forever.
• Ten ammo crates spawn per run. Each refills ALL owned weapons to max, mag and reserve.
• Crates respawn 26 seconds after pickup. Cycling between known crate positions keeps every gun topped up.

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The Graveyard: Map Knowledge

Every run regenerates the map, but the layout rules are constant:

• Boundary: a square fence at ±68 units. Backing up to it gives you a wall; zombies can only approach from the front.
• Mausoleum: sits at the SOUTH edge, at roughly (0, −42). The old assumption that it's central is wrong. It anchors the south wall. Its door faces the center of the map. The building is a solid 4.4-radius collider: use it to break line of sight, reload safely, and kite zombies around it.
• Tombstones: placed on a 6.6-unit grid with a 9-unit clear zone at spawn and a 46% skip chance, roughly 150–200 stones per run. They block movement for you and mildly deflect zombies (1.4× push). Use them as funnels.
• Trees: 16 dead trees ring the outskirts, and they are full obstacles. They create natural chokepoints and cover from sight.
• Lanterns: 5 flickering posts give orientation in the dark. The mausoleum's south position plus the fence makes a reliable compass: find the door, and you know where center is.

Why map knowledge wins runs: zombies spawn at tombstones more than 14 units from you (up to 8 tries, then the farthest stone). That means spawns cluster away from you, but as you move, new groups rise behind you. A patrol route that circles the outer ring past ammo crates keeps spawns in front of you and supplies on your path.

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Step-by-Step Strategy

Sequence 1: Wave 1 Scavenge

1. BEGIN THE SHIFT. Use the 0.6s grace to spot glowing pickups.
2. Kill the first 2–3 zombies with the shovel (one swing each).
3. Jog to the nearest gun pickup. Take the pistol if visible.
4. Clear the rest of wave 1 with pistol or shovel.
5. In the 4.2s break, memorize: ammo crate locations + mausoleum direction.
6. Do NOT pick the gatling gun yet.

Sequence 2: Gear Up (Waves 2–3)

1. Wave 2: grab pistol (12/96). Practice T (swap) and R (reload).
2. Wave 3: find shotgun and SMG. Push toward the rifle pickup.
3. Rifle priority > shotgun > SMG at this stage.
4. Tag 3+ ammo crate positions on your mental map.
5. Keep moving in a wide circle; don't camp the center.

Sequence 3: South Mausoleum Hold (Waves 4–6)

1. Move to the mausoleum at the south edge before wave 4 starts.
2. Stand so the door faces the approaching horde (door faces center/north).
3. Shotgun the first zombies as they funnel along the wall.
4. Swap to the rifle to pick off ranged stragglers.
5. If you take hits, duck behind the building. It blocks line of sight,
   triggers regen, and zombies path around it (buys you 3–5 seconds).
6. When the south push thins, rotate along the fence to the east/west wall.

Sequence 4: Ammo Cycling

1. Know all 10 crate positions. Zone them (N/E/S/W).
2. When rifle reserve drops below 120 (50%), head to the nearest crate.
3. Crates refill every gun at once. Never waste a trip on one weapon.
4. Crate respawn = 26s. A lap around the graveyard takes about that long.
5. Route: crate → kill along the way → next crate → repeat.
6. If you're on the shotgun with 24 or fewer reserve, switch to SMG until the crate.

Sequence 5: Health Crisis Recovery

1. Red flash = hit. Disengage immediately, no exceptions.
2. HP 80+: keep fighting, slightly more cautious.
3. HP 40–60: fall back to the mausoleum or the far fence line.
4. Use the shovel to kill chasers. Free one-hit kills, no ammo spent.
5. Wait 5+ seconds clear of attacks so regen activates (4.2s delay).
6. At 4 HP/s, you recover from 40 HP in 15 seconds.
7. Re-engage with ranged weapons first; shotgun last.

Sequence 6: Gatling Emergency Protocol

1. Use ONLY when cornered with 20+ zombies closing, or wave 8+ horde thinning.
2. Fire in 1–2 second bursts. 100 rounds = 5s of continuous fire.
3. Start looking for your escape route after 3 seconds of firing.
4. At 10 rounds left, move. Begin reload (2.6s) only in cover.
5. Zombies within 10 units mid-reload? Switch to shovel, clear them, then reload.
6. Once per wave is the rule unless you have a guaranteed reload lane.

Sequence 7: Wave Break Optimization

1. Last zombie dies → 4.2s free timer starts.
2. Below 100 HP? Let regen tick first, then move.
3. Above 80 HP? Sprint to the nearest ammo crate and top everything up.
4. Swap to the weapon that fits the next wave's tempo.
5. Reposition: south mausoleum for 4–6, fence ring for 7+.
6. Open the next wave with the shovel for the first kills. Free economy.

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Advanced Tips

The 5-Hit Rule

Every zombie hit costs exactly 20 HP. Track your health in hits, not points:

A hit is a wake-up call, not a speed bump. Reposition before finishing the current kill. The next zombie is already winding up.

Kiting Done Right

Your move speed (5.4 u/s) is 2–4× a zombie's. The graveyard is your arena:

• Group zombies into a trailing pack, then turn and fire at the front of the line.
• Loop them around the mausoleum or a cluster of trees to compress the pack.
• Lead packs past ammo crates so you loot while being chased.
• Never let the pack split you from your escape lane. Keep the fence on one side.

Soft Cap Exploitation

At wave 8+, only 20 zombies can be alive at once, but spawns arrive every ~0.5s. The math is simple: you need to kill ~2 zombies per second on average to hold ground. The assault rifle (255 DPS, ~2.5 kills/sec) barely covers it. That's why the gatling exists. 440 DPS clears the queue in a burst. Use it to reset the cap, then fall back to the rifle.

Weapon Matchups

Audio Cues

Every gunshot is synthesized with a distinct signature: pistol is a bright crack, shotgun a deep boom, SMG a fast high rattle, rifle a sharp bang, gatling a buzz. Zombies groan every 4–10 seconds. A groan nearby means a spawn you might not see. The heartbeat below 30 HP is your cue to stop fighting and start moving.

Config Tuning (Modders)

The CONFIG block at the top of index.html is fully tunable:

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FAQ

Q: Black screen on launch. A: The game needs WebGL + hardware acceleration. Enable it in browser settings and reload. The Three.js script loads from cdnjs, so a stable connection is needed on first load.

Q: How many waves exist? A: Infinite. The formula is 5 × 2^(wave−1). Wave 10 has 2,560 zombies total, though the 20-zombie concurrent cap keeps it playable.

Q: What's the best weapon? A: Assault rifle for general use (28 dmg, 0.11s rate, 72 range, low spread). Shotgun for chokepoints (152 max per blast). Shovel is a permanent one-hit kill.

Q: I missed a weapon pickup. Can I get it back? A: No. Guns spawn once per run. Learn the pickup ring and grab them by wave 3.

Q: Do ammo crates respawn? A: Yes, every 26 seconds. All 10 crates refill every weapon you carry.

Q: Why is the gatling reload so slow? A: Balance. 2.6 seconds is the price of 440 DPS. Never empty it without a clean retreat path.

Q: Can I play on mobile? A: No. The game needs a physical keyboard (WASD + arrows + 1–6). No touch controls exist.

Q: How do I heal? A: Autonomous only. Survive 4.2 seconds without damage and you regen 4 HP/s. There are no health pickups.

Q: Is every graveyard the same? A: No. Terrain, tombstone grid, trees, lanterns, and pickups all regenerate each run. Only the layout rules are fixed: fence at ±68, mausoleum at the south edge, door facing center.

Q: The game feels unbalanced. Can I change it? A: Yes. Open index.html, find the CONFIG block, and edit the values above. The code is MIT-licensed for modders.

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Quick Reference Card

Survival loop:  kite → shoot → regen → loot → reposition
Wave 1–3:       shovel + pistol, gear up, map crates
Wave 4–6:       south mausoleum hold, shotgun funnel, rifle cleanup
Wave 7+:        fence ring patrol, 2 kills/sec minimum, gatling for surges
Ammo:           10 crates, 26s respawn, refills all guns
Health:         5 hits, regen after 4.2s clean, 4 HP/s
Zombie:         100 HP, 20 dmg, 1.55 range, 1.05s cooldown
Mausoleum:      (0, −42), door faces center, LOS cover + kite anchor

Guide refreshed August 2026. Mechanics verified against the live GitHub Pages build and the game source.