IRON NEST: Heavy Turret Simulator is a game about arithmetic. The arithmetic just happens to be bolted to a 5,000 ton dieselpunk walking gun in alternate history Spain in the late 1920s.
It came out August 6, 2026 for $19.99 and it’s sitting at 97% Overwhelmingly Positive across about 6,855 reviews, which is not normal for a game where you spend most of your time drawing pencil lines on a map.
Here’s the way I’d describe playing it. You’re a short-order cook who never sees the dining room.
Tickets come in over a printer, you cook what the ticket says, and you find out later whether you got it right. You never actually look at the customer.
Once that clicks, the whole game gets easier. The gun is the easy part.
What you’re actually doing every mission
The loop is the same every single time. Orders come in on the teleprinter, you plot them on the map table, you run the numbers through the ballistic calculator, you load a shell and powder charges, you dial in bearing and elevation, you run a checklist, you fire, and then you watch where it lands.
That’s it. Everything below is one of those steps done badly by me first so you don’t have to.
Read the teleprinter before you touch a lever
Your orders from High Command and your field reports from spotters both print out here. Read the whole thing before you start moving, the same way you read the whole ticket before you fire up a burner.
Caps Lock toggles your clipboard, and you can click any line of a brief or a report to copy it straight over. Do this constantly.
New players walk back and forth to the printer forty times a mission because they didn’t copy one bearing. Just leave the clipboard up the entire time.
The map table is the real game
The tactical map is a 20×10 grid, lettered columns and numbered rows, and every one of those cells is subdivided into a 10×10 grid of its own. So a coordinate reads like K5 8:0, which is the big cell and then the square inside it.
The big grids are 1000 meters across. The subgrids are 100 meters.
You have three pencils and they are not interchangeable. Red is for measurements that copy to your clipboard, yellow is for measuring lines, and white just draws.
You also have a drafting compass for range, an iris tool that shows you blast radius, and marker icons in red for enemies, green for reference points, and blue for friendlies.
Triangulation, or how to hit something nobody can see
This is the wall. Most people hit it around mission two, look at two spotter reports full of degrees, and have no idea what to do with them.
Here’s the trick. Mark both spotter positions on the map, then draw a yellow line out from each one along the bearing it reported. Where those two lines cross is your target. Then draw a red line from the Iron Nest to that intersection to get your own firing bearing and range.
That’s the whole thing. Two bearings and a ruler beat any guess you were about to make.
If your lines cross somewhere off the map, you plotted a spotter in the wrong spot. Check the positions again before you blame the game.
The ballistic calculator does the hard part
Once you have bearing and range, you feed the calculator your bearing, target type, shell type, range, and number of powder charges. Pull the compute lever and it spits out a fire mission card with your elevation and your flight time.
Powder charges are worth roughly 5 km of range each. Think of the charge count as your coarse setting and elevation as your fine one.
Get the charge count wrong and no amount of careful elevation work saves the shot.
Shell types and when each one is worth it
There are 30-plus ammunition types by the end, but five carry you through the early game. AP is armor piercing, so it’s for hardened positions and anything underground.
HE is your standard high explosive for surface targets sitting close together. HCHE is the high capacity version with a wider blast, which is what you want when enemies are spread out.
SMK is smoke, used to force the enemy to move rather than to kill them. STAR is an illumination round that lights up a section of the map.
One warning that deserves its own line. Once a shell is loaded, it is not coming back out.
Loading and aiming without breaking your own machine
Pick your round with the shell selector lever, then physically ram it into the barrel with the shell rammer. Charges come out of a rotary magazine that holds six, and they get their own rammer, and then you close the breech.
Elevation and rotation both give you two controls. There’s a fast lever for big movements and a fine wheel for precision, and you’ll use both on almost every shot.
Be gentle with the heavy levers. This machine breaks, and fixing it costs you time you probably don’t have.
One real efficiency tip: the turret takes actual seconds to swing around. Start your rotation first, then go load while it’s moving.
Run the checklist every single time
Before you fire, the main console tells you your elevation, flight time, loaded shell type, armed status, and turret bearing. Look at all five.
Then pull the arming lever for the left gun, the right gun, or both, and only then pull the trigger.
Most wasted shells I’ve seen die right here. Somebody dialed a perfect bearing, never touched elevation, and launched a very expensive round into a field 3 km short.
Watch the impact, then correct
Your round lands and you get to see roughly where. Mark it, work out how far off you were and in what direction, and adjust from there.
Do not throw out your whole firing solution and start over. You don’t rewrite the recipe because the steak came back a little rare.
Requisition points and not wasting them
You earn requisition points for killing high value targets and completing objectives, and you spend them on shells, powder charges, recon planes, intel, and emergency repositioning.
My advice early on is boring but it works. Buy information, not fancy ammunition.
A recon plane that tells you exactly where something is will save you more shells than a better shell will.
Beginner mistakes that cost you the mission
Not using the clipboard copy function, which turns every measurement into a round trip across the room. Loading a shell before you’ve computed the solution, then finding out you needed a different one.
Getting the charge count right and the elevation wrong, or the other way around. Forgetting to arm the gun and standing there confused when the trigger does nothing.
And the big one, panicking when the counter-battery clock starts and abandoning a solution you were four seconds from finishing.
Stuff nobody tells you
The in-game notepad is the single best tool in the machine and almost nobody uses it on their first run. Write down bearings, ranges, and corrections as you go.
There’s a free demo if you’re not sure this is your kind of game, and honestly it’s a fair test of whether you’ll enjoy the tedium.
Inside the walker there’s coffee, a record player, and a cat you can customize, and yes, people take the cat very seriously.
In challenge mode, destroying Fire Direction Centers pauses the counter-battery timer. So clear out as much as you can before you take out the last one, because the clock restarts and runs until everything is dead.
Your first mission is going to take forty minutes and feel like homework. Around your tenth it takes eight minutes and starts to feel like a job you’re actually good at.
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Images in this article are from the IRON NEST: Heavy Turret Simulator page on Steam and used under Fair Use.