How this guide is built: Atomic Heart (Mundfish, 2023) is a story-heavy first-person shooter-RPG with a mystery that snaps shut on a genuine twist. The web is already full of two kinds of page for it: minute-by-minute transcripts that give away that twist in passing, and flat “all 72 chirper locations” dumps you scroll while paused. We’ve done the more useful thing. First we teach the systems the game leans on but barely explains — the glove powers, the upgrade and cartridge economy, the relentless open-world respawns and how to switch them off — then we give a spoiler-light mission map, explain how the locks and hacking actually work (the “codes” are not the numbers people expect), break down every boss as a pattern, and only then, behind a clearly marked wall, explain the story and both endings. Cross-checked against IGN’s full wiki and several community completion guides.
Why a step-by-step walkthrough is the wrong tool for Atomic Heart
Atomic Heart is mostly linear between its open-world stretches, so it’s tempting to hand you a numbered route and call it a guide. The trouble is that this game’s whole spine is a slow-drip mystery — who you are, what your chatty glove is really up to, what “Atomic Heart” even refers to — and a transcript that narrates each beat detonates a late twist the writers spend the entire game loading. The other half of the internet over-corrects into pure location dumps: bare lists of collectible coordinates with no explanation of why robots keep swarming you or how the upgrade economy is supposed to flow.
So the goal here is different. Atomic Heart stops being frustrating the moment you understand its rules. The endless respawns become manageable once you know the off-switch. Combat clicks once you stop treating the glove and the gun as separate things. Backtracking and “wait, how do I open this?” evaporate once you know the difference between a pin-pattern lock, a hacking plate and a mechanical puzzle. Learn the systems below and you can read any room Facility 3826 throws at you, instead of clinging to a list of steps that the game’s open areas will scramble anyway.
The setting and who you are (no real spoilers)
You play Major Sergey “P-3” Nechaev, a decorated and short-tempered Soviet agent, in an alternate 1955 where a miracle material called polymer rocketed the USSR into a chrome-plated utopia of helpful robots and floating cities. Your handler is Charles, a sentient AI bonded to your glove — he narrates, banters and explains the world to you, which matters more than it first appears. Your boss, the polymer-discovering genius Dr. Sechenov, sends you to the sprawling Facility 3826 after its robots turn murderous on the eve of his big launch, “Kollektive 2.0.”
That’s all you need going in. Everything else — what the launch really does, who sabotaged the facility, why P-3 keeps blacking out into a candy-coloured dream world — is the game’s to reveal, and we keep it behind the spoiler wall at the end. For now, the important framing is mechanical: P-3 is squishy, the world is hostile, and your two best assets are the glove on your left hand and the resourcefulness to keep it fed with upgrades.
Combat: the glove and the gun are one weapon
New players try to play Atomic Heart as a straight shooter, run dry on ammo, and conclude the combat is unfair. It isn’t — it just expects you to open every fight with the glove. The loop that carries the entire game is simple: crowd-control with a power, then commit with a weapon. A typical exchange is “Shok the robots to stun them, then empty a magazine while they’re frozen in place,” or “Frostbite a melee mob, then shatter them.” Ammo is scarce by design to push you into this rhythm; melee weapons exist precisely so you can save bullets for the things that need them.
Two habits make almost every fight easier. First, dodge constantly — the dodge has a generous window, and one early skill turns it into a panic button (see below). Second, retreat into doorways and corridors so robot mobs funnel instead of surrounding you, then thin them with a charged power. Against the relentless humanoid robots especially, kiting them through a chokepoint and cracking them with electricity is far safer than standing your ground.
The glove powers and the upgrade economy
Your glove has several power trees, each gated behind the talking, flirtatious NORA vending machines that double as your save points and workbenches. You spend neuropolymer on glove skills and use blueprints (found in the Testing Grounds) plus salvaged resources to build weapon modifications. The single most important thing to know: you can refund every skill and every weapon mod for a 100% return at any NORA. There is no permanent wrong choice, so respec freely for a tough boss and switch back afterward.
The power trees worth your early polymer:
- Shok — an electric discharge that stuns enemies and melts robots. The upgrade Chain Lightning (and its extensions) lets it leap between targets, turning it into crowd control. This is your bread-and-butter opener.
- Frostbite — freezes enemies solid for free shatter damage; superb against organic mobs and great for buying breathing room.
- Mass Telekinesis — lifts and flings objects (and enemies). With its slam upgrade it’s widely considered the strongest offensive power in the game, and it’s essential for several Testing Ground puzzles.
- Polymeric Jet — sprays polymer that you can then ignite or electrify, and is required to hold certain timed doors open.
- Polymeric Shield — a deployable shield; the Kinetic / Neuro-Polymer Reflector upgrades bounce damage back and trivialise some fights.
- Energy Management — quietly one of the best trees, because it lets you chain powers far more often instead of waiting on cooldowns.
On the Character (body) tree, prioritise one combo above all: Sleazeball, which grants invincibility frames during a dodge, paired with Second Wind, which gives you a second consecutive dodge. Together they turn dodging into a near-foolproof escape and make the game’s nastier bosses dramatically more forgiving. Wild Boar (more health) and the backpack-capacity skills round out a comfortable early build.
Weapons and cartridges
You build a small arsenal over the game — the melee Swede axe and throwing Zvezdochka blades, sidearms, the KS-23 shotgun, the MP SMG, the Kalash rifle, and exotics like the Dominator, Fat Boy, Electro and the late-game Railgun. Don’t agonise over “the best gun”: because mods refund for free, the practical move is to fully upgrade one or two weapons you enjoy (the Kalash and a shotgun is a fine spine) and feed everything into them. Fully maxing any single weapon also pops the Great Inventor achievement, after which you can disassemble it and reclaim the materials.
The system people miss is cartridges — elemental ammo (fire, frost, and so on) that you load into a weapon’s cartridge slot. You first have to install the cartridge slot as a mod at a NORA, then equip a cartridge from the weapon wheel; you’ll see a canister appear on the barrel. Cartridges are how you exploit elemental weaknesses — fire melts the plant-based enemies and certain bosses, while electricity is king against robots — and they’re the cleanest way to deal with foes that shrug off plain bullets.
The open world, the respawns, and the off-switch nobody mentions
The biggest source of open-world misery is that the surface robots respawn endlessly: cameras spot you, an alarm sounds, and flying repair drones resurrect every machine you just destroyed. Fighting through this head-on is a waste of ammo. The game never explains the counter clearly, so here it is.
In each major open area there is a Controller terminal and an Antenna Relay. Use Scan mode near any active camera and follow the red lines back to the green-highlighted Controller; interact with it to pull up a camera map. Locate the small cylindrical hut with spinning antennas (the Relay), centre it on the map, then physically travel to it and choose OVERLOAD on its panel. That destroys the relay and disables every mechanical enemy in the zone for about fifteen minutes — long enough to loot, explore or clear a Testing Ground in peace. It’s repeatable, and it only works after you reach the main open world (you cannot do it in the very first outdoor stretch). One bonus: enemies you freeze can be shattered for a permanent kill that the repair drones can’t undo.
Doors and locks: why the “codes” aren’t numbers
People search for “Atomic Heart door codes” expecting a list of four-digit numbers to type in. That list mostly doesn’t exist, and it’s worth understanding why — it saves you a lot of confused googling. There are really three lock types:
- Pin-pattern locks. The common ones aren’t numbers at all: a grid of pins shows a shape, and you simply have to copy the pattern, which is drawn or scrawled somewhere nearby (on a wall, a note, a blackboard). The answer is always in the immediate area — scour the room rather than hunting for a code online.
- Hacking plates (blue lock pads). These trigger one of two timing mini-games (explained below). No code — just reactions.
- Mechanical / dial puzzles and physical keys. Some doors want a key you pick up from a corpse or a connected puzzle (for example, the Crop Museum’s “Circle Key”), and some are stand-alone contraptions like the chunky valve dial pictured above.
So when a door stops you, the honest answer is almost never “enter 1955.” It’s “look around for the pattern, the key, or the blackboard,” and the named lockboxes the wikis catalogue — the Vavilov cable-car booth, the VDNH Tokamak exhibit and Crop Museum moon lock, the Theatre concessions door, the Pavlov office — all resolve that way. We deliberately don’t print “codes” for them because for most they’d be meaningless out of context; the genuinely useful tip is to know what kind of lock you’re looking at.
The two hacking mini-games. Game 1 (timing): a ring of coils surrounds a central timer; a red light sweeps the perimeter, and you press the button the instant a blank node lights red to retract that coil. Don’t double-tap a node — hitting one twice re-extends it. Retract them all before the timer ends. Game 2 (colour-match): each coil is colour-coded; rotate the coloured dots with the triggers so each dot lines up under its matching coil. Solve one dot first, count the notches to the next, and the rest follows. Both are pure dexterity puzzles — there is nothing to memorise.
The Testing Grounds (Polygons): what they are and whether to bother
Scattered across the surface are eight optional dungeons called Testing Grounds (the “Polygons”): numbers 1, 2, 6, 8, 9, 10, 11 and 12. Each is a self-contained puzzle box built around the same toys — magnetic platforming, ball-and-holder doors, spinning-valve mechanisms and Polymeric-Jet timed gates — and each holds three reward chests (Lootyagins): bronze, silver, and a gold one tucked near the exit. Crucially, the Testing Grounds are where you find the weapon-mod blueprints, so they’re not just busywork: if your guns feel weak, you’re probably skipping these.
Practical notes: most entrances are opened by scanning “Dandelion” cameras through a terminal, and a couple (Polygon 8, and the story-gated ones) only unlock as you progress the campaign. The movement-speed and dash skills make the platforming markedly easier, and Mass Telekinesis solves several of the ball puzzles outright. Two house a boss: Plyusch, a plant creature in Polygon 9 that’s immune to gunfire (use melee and fire), and a Natasha-type ballerina robot in Polygon 12 (heavy weapons like the Fat Boy make short work of it). Collecting all 24 Lootyagins earns More Than Profit; simply entering and clearing all eight covers the Explorer and clean-up achievements.
A spoiler-light mission map
The campaign runs through a fixed sequence of zones. Here’s the shape of each with no plot turns given away — just where you are and what it introduces.
| Zone | Setting & what it introduces |
|---|---|
| Prologue | The floating city of Chelomey and Sechenov’s palace. A long, set-piece tour that teaches movement and tone before the violence starts. |
| Vavilov Complex | The first big underground lab. You meet Granny Zina and the man-eating NORA machines, learn the core combat loop, and face early mutants. Get comfortable with Shok here. |
| Forester Village | A short surface breather between labs — your first taste of the open world and its respawn problem. |
| VDNH | The exhibition complex and the main open world proper. The Hedgie boss bookends it, and this is where the Controller/Relay off-switch and most Testing Grounds become relevant. |
| Sechenov Research Centre & The Theatre | A tense indoor stretch and a theatrical set-piece, guarded by the Belyash arena boss and the Natasha ballerina robot. |
| Pavlov Complex | The infirmary and labs where the story tightens its grip and the big reveals begin landing. |
| The Academy of Consequences | The endgame, reached via the Lighthouse. The Dewdrop boss guards the approach, and the point of no return and your ending choice live here. Tidy up collectibles first. |
The bosses, and how each one is really a pattern
None of Atomic Heart’s bosses are twitch tests; each is a short loop you repeat. Once you see the pattern they’re straightforward, and the Sleazeball/Second Wind dodge combo defangs all of them.
- Hedgie (VDNH) — a giant rolling machine. Use the environment: there’s a way to electrify the arena and let Hedgie hurt itself, which is also how you earn the no-weapons Strike achievement. Keep moving and bait its charge.
- Belyash (The Theatre) — an arena bruiser. Doable with guns, but melee-only (axe or Zvezdochka, with a fire cartridge) earns Chop Chop Chop; dodge through its swings and punish the recovery.
- Natasha — a fast ballerina robot. Stagger her with Shok or Frostbite to interrupt her dash combos, then burst her down; heavy weapons end it quickly.
- Plyusch (Polygon 9, and seen in the story) — immune to gunfire. This is the one fight where you must go melee, and fire (a fire cartridge, or the “Raspberry” consumable) is extremely effective. Don’t waste bullets on it.
- Dewdrop (before the Lighthouse) — a large robot guarding the endgame approach; standard kite-and-stun rules apply, with cover to break line of sight.
- The Twins (finale) — a two-phase fight. You face one twin, then both together. Come stocked with ammo, healing and a fully upgraded weapon; lean on dodge i-frames, freeze them when you can, and focus one at a time in phase two.
Collectibles as categories, not a flat list
If you’re chasing 100%, treat the collectibles as a handful of systems with rules rather than one giant checklist. The main families are:
- Chirpers (the “burning ears” audio collectibles) — voiced recordings scattered through every zone; the bulk of the collectible count.
- Talking Corpses — bodies you can interrogate for lore and the occasional code or key. Some completion guides note this tracker was buggy at launch, so patch up to the latest version before grinding it.
- Blueprints — weapon-mod schematics, almost all found in the Testing Grounds.
- Enemy scans — scan each enemy type once with the glove’s scan mode.
- Lootyagins — the bronze/silver/gold chests inside Testing Grounds (24 total).
The merciful news is that the open world is freely backtrackable, so very little is permanently missable — the main thing to do before the Academy of Consequences point of no return is sweep any zones you left unfinished. The one habit worth keeping from the start is to scan everything and pop the audio logs as you pass them, so you’re not re-clearing whole regions later.
Difficulty, saving, and a clean 100% plan
Atomic Heart has a manual save system at NORA machines plus autosaves, with several slots — save often, especially on the higher difficulties where a bad ambush can erase real progress. The hardest difficulty, Armageddon, is achievement-friendly for confident players because it overlaps with the “survive” trophies, but there’s no shame in a lower setting; the story and all collectibles are reachable on any difficulty, and the game is completable however you like to play.
For 100%, the efficient route is: play through once thoroughly, clearing all eight Testing Grounds for blueprints and Lootyagins, scanning every enemy, and grabbing chirpers and corpses as you go. Knock out the missable-on-paper combat achievements when their fights come up (the no-weapon Strike on Hedgie, melee-only Chop Chop Chop on Belyash). Because skills and mods refund freely, you can fully max a weapon for Great Inventor and then reclaim the parts. If a collection achievement refuses to pop despite a full counter — a known launch quirk — close and reload the game before assuming you missed something. The base campaign runs roughly 20–25 hours; full completion with all four DLC packs stretches well past 40.
⚠️ Spoiler wall: the story and both endings
Everything from here spoils the ending. Stop reading if you haven’t finished the game.
The launch you’re protecting, Kollektive 2.0, isn’t the egalitarian dream Sechenov sells. It implants “Thought” devices that send users into a fantasy dream-world called Limbo while the network pilots their bodies — total mind control, with Sechenov (the “alpha connector”) at the top. Worse, the rogue robots weren’t hacked by the saboteur Viktor Petrov at all; he merely switched on a combat mode every facility robot already had. That hidden mode is the real “Atomic Heart” plan: the Kremlin intended to ship these robots to America as labour, then remotely flip them into an invading army. Petrov was trying to warn the U.S. before he’s killed; his partner, Dr. Larisa Filatova, defects to help you.
P-3’s own blackouts are the key. He’s a war veteran whose wife, fellow agent Ekaterina, died on a mission in Bulgaria that left him brain-damaged and prone to homicidal rage. Sechenov rebuilt him with prosthetics and a Voskhod implant that wiped his memories and can drop him into Limbo on command — and every time P-3 falls into Limbo, his body is switched to combat mode and slaughters everyone nearby. That’s how Molotov and, later, Filatova die by his hand. The ballerina Twins guarding Sechenov were even built using traces of Ekaterina’s combat style. And Granny Zina turns out to be his mother-in-law, quietly shepherding him toward the truth.
The biggest twist concerns Charles, the glove. He’s the polymerised consciousness of Dr. Chariton Zakhirov, a scientist Sechenov supposedly drowned in polymer. In the Fight ending, P-3 storms the palace, beats the Twins and shoots Sechenov — who, dying, swears he never sent P-3 into Limbo. The real puppeteer was Charles/Zakhirov all along, feeding P-3 a curated version of events to turn him against Sechenov. Charles then ejects from the glove, merges with the polymer data-bank monster to grow a body, kills and absorbs Sechenov, and reveals an even grander aim: forcing humanity to “evolve” by merging with polymer. He sends P-3 into Limbo forever, to live out eternity with a robotic echo of his dead wife — a bleak punchline that reads as the “true” ending.
The shorter Leave ending is P-3’s skepticism winning out: he reasons that if Sechenov truly controlled him, none of the night’s events add up, and notes that Zakhirov — who invented the mind-control Voskhod in the first place — is hardly the innocent he plays. He rips Charles out of the glove, stamps on him, and walks away to the countryside, leaving Sechenov to his plans. It looks like the cowardly choice, but the Fight ending quietly confirms it’s the wiser one: Sechenov is a tyrant, yet Zakhirov is worse. Either way, the game ends on ambiguity built for a sequel — which is exactly why a step-by-step transcript that spoils all this in passing does the game such a disservice.
The verdict
Atomic Heart is a gorgeous, uneven, fascinating game that punishes players who treat it like a generic shooter and rewards the ones who learn its grammar. Lead with the glove, keep one weapon fully fed, switch off the open-world respawns, read each lock for what it actually is, and treat the bosses as routines — do that and the difficulty smooths out, leaving you free to enjoy the lavish retro-future world and the genuinely sharp twist waiting at the end. Skip the transcripts, learn the systems, and let the mystery land the way Mundfish intended.
Guide by Marvin Tang. Systems, codes and boss notes cross-checked against IGN’s Atomic Heart wiki and community completion guides on Steam. Screenshots are official Mundfish promotional images; the trailer is embedded from Mundfish’s official YouTube channel. Atomic Heart is a trademark of Mundfish; this is an independent, unofficial guide.