- Dev Diary #1 - The Building Blocks - 8 July 2026
Hello, Pioneers, and welcome to the first Harwell: Mars Industries dev diary. If you're new here, hello! I’m Caleb Houlding, solo developer of Harwell: Mars Industries, along with publisher Aquila Interactive. It's great to have you here!Today we’re looking at the building blocks of Harwell: Mars Industries, and we'll be showcasing the implementation of various buildings, along with their resources and the code that makes them run. You can find today’s dev diary in video form right here:Before we go on, the following are still a work-in-progress and could change before the final release. The First Step Mining for resources is the first step to success. This means that when starting out, you’ll need to place your HQ carefully to maximise the resources available to you, but once you’ve built it, you’ll need to get started quickly to get ahead. Let’s take a look at the buildings available…
- New Publisher Announcement! - 28 April 2026
Mars is open for business! Developer Caleb Houlding is partnering with publisher Aquila Interactive to announce Harwell: Mars Industries, a sci-fi economic strategy game set on Mars, coming 2027.This is the start of an exciting journey, and we'd love for you to head to the Store page, wishlist and come along with us for the ride in our Discord. What is Harwell: Mars IndustriesEach corporation begins on an equal footing in Harwell, a singleplayer and multiplayer economic strategy game set on the Mars. Build your company, control production, and trade in a dynamic economy where shifting supply and demand can lead to vast riches – or drive you into bankruptcy.Your path to victory is simple: Accumulate wealth, outmaneuver your rivals, and buy out every competitor to establish a total monopoly.FeaturesA brand-new planet full of resources to plunder - mine valuable resources directly from the…
- v0.20.4 Patch - 13 April 2026
New FeaturesFriends system with Steam and Nakama integration — add friends, see their status (online, in-game, in-lobby), and invite them directly to games.Beautiful Shadows toggle in Graphics settings for the new lighting pipeline.Game end screen redesign with full-screen overlay, financial graphs (revenue, expenses, company value, profit, debt), per-resource production tables, and complete player leaderboard ranked by company value.Spectate mode for eliminated players — watch the rest of the game without access to building, demolishing, or sabotage menus.Expanded lobby hosting and connection flow with signal-driven status updates.ImprovementsHost migration now elects a new host automatically when the current host disconnects, with high priority notifications.Host disconnection detection prevents players from getting stuck in zombie states.Reconnect prompt now validates against live Na…
- v0.20.2 - 6 April 2026
New FeaturesCosmetic delivery ships now fly between your HQ and distant buildings with smooth arcs, steering, and dynamic shadows.You'll now get a daily notification when you don't have enough workers to keep up with demand. ImprovementsThere's now a loading overlay while the lobby loads so it doesn't just feel like nothing's happening.The sync overlay got a full redesign with a cleaner layout and a per-player indicator showing who's ready.The Start button now waits until all players are fully synced before letting you begin.The reconnect prompt looks nicer now with a vertical button layout and a fade-in animation.Multiplayer authority checks are more consistent across the board for better host/client handling.Bug FixesFixed memory leaks in effects, singletons, and UI systems that were leaving stale references around.The game now properly resets its sync checklists and waits for full wo…
- v0.20 - 5 April 2026
New FeaturesThere's a brand new sabotage system with 17 cards across five categories: destruction, disruption, finance, intelligence, and labour.The black market menu lets you browse, buy, and manage sabotage cards to build your hand.You can now control game speed with five settings (x1 through x16), and if your system can't keep up it'll automatically step down — in multiplayer, everyone has to agree on speed changes.You can now demolish your own buildings, complete with particle effects and animated destruction.Buildings are now clickable with an outline shader that highlights them when you hover.A new notification panel shows game events with icons and visual feedback as they happen.The finance sheet got a full redesign with detailed tooltips and proper transaction tracking.The build menu has been redesigned with a floating bottom-left layout and category panels for quicker access.Yo…
- Fanciful Constructions - 9 March 2026
Hello! Just a post about a relatively small feature that I think will make a large impact to gameplay: construction time.Building instantly is no fun, so Harwell now has a fancy new construction shader which dynamically builds the building in sync with its construction time - Ooooo!This should add more strategy to when to place buildings - you have to be patient for your profits! Currently, all buildings will take 10 sols to build, but this may change after testing.In the future, I may improve this to add small cranes to construction sites or show some sort of under-construction texture. Maybe a blank plot of land. I'm open to ideas! For now I think it looks pretty good though.ModdingAs with many things in Harwell, construction time is moddable by changing just one value in the buildings.json file:The value represents sols, which is now the in-game time used. 1 sol = 5 seconds.That's al…
- v0.19.3 Patch - 3 March 2026
TL;DR Players should now see HUGE performance improvements, up to +150% on low-end devices, and there's MOAR graphs. New FeaturesMarket multi-threading for improved performanceCentralized ProfitCalculator class for consistent profit calculationsPlayer profit tracking with actual purchase costs and sales revenueFinancial graphs added to the financial tabCustom monitoring statistics in the engine for AI and market informationModdable colony namesImprovementsThread manager now auto-detects number of CPU cores and sets threads accordinglyOptimized AI timers to dynamically start/stop based on activity stateCentralized color overlay to building managerCanvasItem caching and optimizationsRemoved await get_tree().process_frame in _process() callsAdded static types for various variablesOptimized lobby syncing for better performanceMax inventory values centralized into a constantColony spawning c…
- v0.19.2 Patch - 27 February 2026
TL;DR The visuals won't be quite as glitchy, tooltips will consider inventory goods, and multiplayer will work a bit better.New FeaturesDisabled tooltip for HQ building previewDisabled physics interpolation for building previewImprovementsThe construction tooltip now takes inventory goods into consideration when calculating total costBalance changesMultiplayer fixesBug FixesFixed an issue with the colour overlay not applying properlyFixed an issue where player inventory goods wouldn't be used for constructionFixed an issue where players could unpause each other
- v0.19.1 Patch - 23 February 2026
TL;DR The AI is a bit more competent, and there should be a bit more polish.New FeaturesAdded housing and labour iconsAdded auction scenes and UI (for upcoming updates)Added sparks particle effectImprovementsAI behaviour improvements for better early game selling and industry building prioritizationAI companies now invest into different industries rather than duplicating effortsBalance changes to resources and buildingsOptimizations to various utility scripts (DataChecksum, FileCopyUtility)Compressed particle texturesUpdated color definitionsBug FixesFixed game staying paused when started (except on host)Fixed multiplayer and syncing issuesFixed lobbies closing when exceeding 12 playersFixed issues with financial dataFixed issues with sol countFixed signal-related bugs and renamed old signals after time system changesUpdated time variables to match new Sol systemSteam sync agent fixesCo…
- Nakama - 6 February 2026
Greetings! I'm Caleb, developer of Harwell. As part of update 0.18 Harwell got a huge update - actual, functional multiplayer, and it involved an ever so slight complete rework of the multiplayer system in the game. Here's what it entailed!Main MenuThe main change in the main menu is this new panel on the left side which displays your Steam and Nakama IDs and lets you update your display name:You'll also get a little setup screen when starting the game which asks if you want to link Steam to your Nakama account, if you click no it will just use Nakama and store a device ID which is anonymous but can be used by Nakama to know if you're playing from the same device. This does mean that if you don't sync it to Steam and then move to another computer your multiplayer progress may be lost! By identifying using Nakama IDs it means people can play multiplayer outside of Steam or if Steam is do…
- v0.18.5 Patch - 6 February 2026
New FeaturesAdded icon graphics for uranium.ImprovementsTidied up the market entries.Re-organised the UI controls panel and labelled it.Balance changes for Power resource.Updated the clock & day counter to use Sols instead.Updated the debug menu to work with the new Sols.AI Improvements, including better building selection and performance improvements.Updated to Godot 4.7.Updated Start Game button theme.Bug FixesFixed an issue where players would not get the profit from dividends.
- v0.18: Multiplayer! - 2 February 2026
New FeaturesAdded Sulfur and Uranium map textures ready for implementationAdded Sulfur, Concrete, Explosives, and Soil icon graphicsRedesigned admin menu/pause menu and moved them from the bottom right (now bound to Escape key)Redesigned lobby screen with rearranged game settingsReplaced static parallax background stars with dynamic twinkling shaderRestructured AI behaviour system to be fully moddableAdded new particle effects (currently unused)Added buttons to debug menu for changing player namesAI names are now moddable via /data/names_ai.jsonAdded AI name category selection to lobby settingsImplemented the basics of a sabotage system (sabotage_card, sabotage_effect, and sabotage_manager)Added sabotage effects to data folder with modding guideAdded Sentry integrationAdded Nakama integrationAdded main menu profile display showing player IDs and informationAdded PostHog analytics integr…
- v0.17: Building Modifiers - 15 January 2026
New FeaturesImplemented a new system to dynamically adjust building performance based on terrain and proximity.Added for real-time evaluation of placement conditions.Modifiers are now fully integrated into production logic and financial previews.Added a modifier preview tooltip during building placement to show active bonuses or penalties before you build.Added efficiency modifiers for Wind Turbines based on nearby mountains and building interference.Introduced penalties for buildings disconnected from the HQ based on their distance.Integrated GodotSteam and Spotlight add-ins for enhanced multiplayer and editor functionality.Added Signalbus events for building lifecycle tracking (placement and removal).Added a comprehensive modding guide for the Building Modifier System.ImprovementsRedesigned the tooltip system for better consistency and improved screen boundary detection.Updated buildi…
- Building Modifiers II: Electric Boogaloo - 12 January 2026
Hello! It's Caleb, developer of Harwell. I decided to write a part two to my last development showcase, Building Modifiers. I've made some improvements and added some polish so this one is going to be much less technical and much more screenshot-ey.Tooltips!I've reworked and improved how modifiers are displayed in-game. As well as polishing the tooltip when placing buildings, the modifiers now show in the tooltips for construction buttons automatically, and also show in the building tooltips when you hover over a building (showing both the modifier, a description, and its effect).In terms of modding, the only thing that would need creating in order to support the tooltips is localisation. It automatically adjusts the tooltips based on the JSON files for the modifiers - after all, the work in the base game exactly how they'd work for a mod. Easy. Simple.Example TooltipExample of how it a…
- Building Modifiers - 28 December 2025
Development Showcase: ModifiersHello, it's Caleb, developer of Harwell. It's been a little while so I thought I'd write a festive write-up of what's been going on, and the most recent implementation in the game - building modifiers. Modifiers have taken some work to implement - having to build in JSON files, adjusting the building system, building them into the inventory system, and more. They're almost complete so I wanted to write a dev diary about the progress so far. I hope everyone has had a lovely Christmas this year!Updates to AISince the last update, I've been balancing the AI and configuring it to make sure it's competitive but not crazy. Initially, the AI was quite passive - it would barely build after the first few buildings and it didn't quite know how to manage its money properly. Now, it's quite the opposite! The AI is aggressive and actually overbuilds, it's quite tricky…
- version 0.16: Building a Better Tomorrow (Without the Lag) - 16 October 2025
Performance & OptimizationImproved base_building and player_manager to fix performance issues from buildingsCreated the building_manager to oversee building purchases and perform batching & queueingOptimized the building manager to prevent lag spikes on each tickRefined transaction batch processing to improve performanceUpdated the game to run on every tick instead of every 5 ticksUI/UX ImprovementsAdded arrows to main menu buttons on hoverIncreased the scale of the HQ pixel effects (was too small)Adjusted the color and opacity of the atmosphereFixed the stock ownership bars to display properly when stocks are purchasedBug FixesFixed issues with the market_menu not receiving inventory updatesFixed issues with the financial menu not receiving financial dataDisabled the debug_menu transaction history logging when the debug menu is closedLocalizationAdjusted localisationFixed most localisa…
- AI-Controlled Companies - 5 October 2025
Development Showcase: AI-Controlled CompaniesHola, it's the developer of Harwell - Caleb - here! In this development showcase, I'll be covering the implementation of AI-controlled players and how they'll interact with the systems and compete with the player.This Dev diary is not about LLMs and stuff, just about the game "AI".Names & CharacteristicsThe AI get given randomly selected names based on historical space-related scientists. Not just from Europe or the Americas, but from Asia, Africa, and the rest of the world also. The list of names will eventually be a moddable attribute so players can add their own names.The AI are also treated the same as players - given a player colour, company values and stock prices, and everything else a player gets. The game considers them a player, just with AI-specific functions in certain areas (an AI-specific market purchase, AI-specific constructio…
- Renderer (Vulkan vs OpenGL) - 2 October 2025
Development Showcase: Renderer (Vulkan vs OpenGL)Afternoon wherever you are in the world! I'm Caleb, developer of Harwell. If you're not familiar with it, it's a capitalist RTS where you build up factories to make stacks of profit to buy out the other players, and it's pretty neat if I do say so myself.I've decided to move the game from Godot's Compatibility renderer (which uses OpenGL) to Forward+ (which uses Vulkan). It's been coming for a little while now but I finally decided to make the decision, and I thought some people might be interested in the details!Compatibility vs Forward+If you don't know, Godot has multiple renderers which you can choose from: Forward+, Mobile, and Compatibility. Forward+ being the modern Vulkan renderer, Mobile being slightly older but compatible with more low-power devices, and Compatibility being the OpenGL renderer which has great compatibility and p…
- Quality of Life & UI Overhaul - 11 September 2025
Development Showcase: Quality of Life & UI OverhaulAfternoon! I'm Caleb, developer of Harwell. This feature showcase will be about the smaller improvements that make the game feel SO much greater. It might not be a long dev diary, but this one has greatly improved game feel.I'll go over auto-selling to replace the tedious process of buying and selling goods, tooltips that display figures on the construction buttons, net profit calculations, and balance figures. One primary aim of this UI overhaul has been to reduce how full and cluttered the screen is, and to reduce the vertical size of the menus so they don't span the whole screen.Information BarNow the Finance & Market menus are merged into one, it's important that the useful information always stays visible - cash and debt. I've moved those numbers into their own top bar which is separate from the market and stock menus.Auto-SellYou…
- Modding - 13 August 2025
Development Showcase: ModdingHiya, it's Caleb, developer of Harwell. If you've been keeping up with these I'm sorry for the delay on this one! I've been focusing hard on improving Harwell and rewriting large sections of it to be more modular so I can build the game with modding in mind.ChangesOne thing I was thinking about was moddability and modularity in the game's design. I potentially want to open the game up for modding, even just the foundations of it for now, and needed to consider this in how I design and implement features. I realised that I'd better do this sooner rather than later, as it required rewriting large parts of the code in a way that would open the game up for modding.In order to do this I had to implement a way for the game to have it's base game resources and then check for additional content and mods when loaded up that it can overwrite the base resources with.I…
