
Design. Simulate. Detonate. As a junior engineer at the Kurchatov Institute, you design atomic devices to satisfy the demands of the State. A hardcore physics game simulating hydrodynamics, neutron transport, and thermonuclear fusion.
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About
NUCLEAR DESIGN BUREAU is a hardcore sandbox engineering game where you design and test nuclear devices.
You are a junior engineer at the Kurchatov Institute. The State gives you a target and a warehouse full of dangerous materials. Some directives limit what you are allowed to use. Your job is to build a device that does what the directive asks.
This game is built in the open. The campaign, the physics and the tools change based on what players build, where they get stuck, and what they ask for. That is the whole reason it is in Early Access.
HOW IT WORKS
- Receive a directive: Technical requirements and constraints, with material limits on some jobs.
- Measure it by hand: The criticality lab is first person. Set the core in its cradle, lower the beryllium reflector onto it, and watch the counter on the wall while the live k estimate climbs toward one. Push it too far and the dose lands on your hands, not on a number.
- Design: Paint materials straight onto the blueprint grid. Build the primary, the casing, and the supporting systems.
- Simulate: Hit the red button and run full detonation physics in real time.
- Refine: If it fizzles, fails, or wastes material, work out why and change it.
CORE FEATURES
- Physics-Driven Simulation: Shockwaves, heat, radiation, and chain-reaction behavior are modeled in real time.
- Criticality Lab: A first person room where you handle the real parts. Live Monte Carlo k-effective, a wall counter that lags the way the instrument actually would, and radiation exposure that shows on the operator instead of in a readout.
- Detonation Viewer: Observe detonations as they unfold, with live visual feedback on blast behavior.
- Campaign Directives: Structured mission progression with technical goals and constraints.
- Sandbox Mode: Unlimited experimentation with full design freedom.
- Iterative Engineering Loop: Build, test, diagnose, and optimize.
EARLY ACCESS STATUS (CURRENT BUILD)
The current Early Access build is playable end to end and includes the core gameplay loop:
- Design -> Simulate -> Detonate -> Refine
- The criticality lab
- Sandbox mode
- Campaign directives
- Save/load systems with ongoing stability improvements
This is an active development build. Expect balance changes, physics work, and campaign iteration during Early Access.
EARLY ACCESS ROADMAP (SUBJECT TO CHANGE)
Physics and Simulation
- Refining the detonation viewer (better shockwaves, damage radius and thermal radiation modeling, destructible buildings and targets)
- Finer grid resolution for stronger PCs and GPUs
- More to do in the criticality lab
Campaign and Content
- Expanding the campaign with unique challenges
- Many more directives/missions
- Voiced campaign
- Additional bomb concepts (high-radiation designs, clean bombs, neutron bombs)
- More advanced materials
Presentation and Audio
- More music tracks
Community and Meta
- Public leaderboard
- Statistics on every campaign directive, so you can compare how efficient your design was against everyone else's
DEVELOPMENT APPROACH
Design. Simulate. Detonate.
Early Access is where this game gets shaped in public. What players build, where they get stuck, and what they ask for decides what gets worked on next. Most of the day to day happens on Discord.
"The atom is not a soldier, Comrade. It is a force of nature. We merely tell it where to go."
Genres
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Engagement
Reviews
Themes across 93 recent reviews and how positive each mention is. A keyword signal, not full sentiment analysis.
Reviews
Had no idea science was this fun 10/10
Controls and interface are a bit unpolished but it does not ruin the experience overall.
I really enjoy the idea, however, the tests and simulations take an extremely long time to complete. I do understand that this is in early access but holy smokes is this ever kind of a drag. I do recommend this game for those who are interested in nuclear physics, but I would like to see optimization to help the speed of the tests and simulations. Also the first person annex is sluggish and I am running an ASUS TUF GAMING laptop in turbo mode and I am still having issues. 6/10 until improvements are completed.
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Languages: English
Hours played at review time, across 93 reviews with recorded playtime.
positive critical· bar length = how often the theme comes up
An interesting 2D FNE sim for nuclear weapons, but in a very rough shape. Still, worth the current asking price, but don't expect masterfully crafted experience from this. But, I can't lie, I have had a lot of fun testing different kinds of nuke designs just to see how many of them are viable. If you've enjoyed falling sand games, this is pretty much like one of them with a nuclear theme. Now onto the downsides. Much of the game has hallmarks of vibecoding. I personally don't think it's a mortal sin, but pretty clear that a passionate and a capable human has NOT been involved in most apparent aspects of the game. Examples include: GUI and pause menu layout, mission texts and the manual, references to non-existent or dysfunctional game mechanics, UI bugs readily apparent from a dozen minutes of playtesting. There's a 3D first-person laboratory where you can recreate the demon core experiment, but it's basically asset flip unity game quality, and does not tie to the actual game at all. It would be better if it was scrapped entirely and recreated in the 2D engine. Regardless, fission weapon design parts of the game work well, to the point I think it could be a good educational aid. Fusion mechanics have some very serious deficiencies. I am quite afraid that the developer might have bitten off a much bigger piece than they can chew. It is already a commendable achievement to ship a (somewhat) functional game in the first place, but it remains to be seen if he can finish what he started. At least the current asking price is reflective of current quality.
I think this has strong bones, but it is very rough currently. Main issue I have is the basic editing controls (the main thing you use while playing) are atrocious and extremely clunky. Fullscreen and windowed fullscreen settings don't seem to work for me either. Still worth the low price of entry at the moment though if this piques your interest.
It's definitely early access, there are bugs, and the simulation is slow, but it's doing hydrodynamic math, it was always going to be slow. If you can handle it being slow, then 10000% recommend it. It's everything I could have asked for, and more. It's truly beautiful.
Managed to get past 500kT quite fast :D, there is still a lot of work to do but still enjoyed it, looking forward for improvements. The only annoying thing is that I can't delete the already placed components, or maybe I am dumb.
Congrats, you are now officially both on the list and on the spectrum. And probably on a yet another list if you have all the achievements.
I enjoy the concept. And it's probably my PC, though I've heard similar reports from others, but I can leave a simulation running for several minutes and be about 3 microseconds in. With a much larger 71kt device, it was laggy but I could actually run it. An 11kt device, following the same design but scaled down, froze my entire PC, so I'm not entirely sure what factors are at play regarding performance(it's probably obvious and I'm just being stupid). I do enjoy the game when it actually goes fast enough to not just look like a still image. I'll maybe come back to it more when I get a better PC.
Ok for the price. Heavy AI use.
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