Metal Fatigue Retrofit

Metal Fatigue Retrofit

A distributable patcher that fixes two long-standing bugs in Metal Fatigue (Zono/Psygnosis, 2000; rights now at Nightdive/Atari):

1. Global memory-based unit limit — the game caps in-use game-object allocations at a hard-coded 8 MB inside a fixed 10 MB pool, blocking unit production long before any real memory pressure. Independent of how much RAM you have. This was a huge problem in Matches with 6+ players seeing as unit production got blocked quite early due to the unit limit being global.
2. Crew-name limit (~50 per faction) — combots draw pilot/crew names from a fixed 50-name pool per faction. The names come back when a crew dies, so this is a cap on how many combots you can field at once; reach it and production is refused with a leftover developer line ("Couldn't find a name for this crew!").

Download

Two equivalent downloads — both do the exact same thing:

• Standalone (recommended) — MetalFatigueRetrofitPatcher.exe. Just run it. Nothing is installed, nothing is left behind. Undo any time with the built-in Restore original button. (The .zip on the release page holds that same exe together with the README and the licence.)
• Installer (optional) — …-Setup.exe. A classic wizard that adds a Start-Menu entry and an Add/Remove-Programs uninstaller (which can also restore the original). Handy if you prefer that, but it patches your game exactly the same way.

Both are unsigned, so Windows shows the same "unknown publisher" prompt either way — see Is this safe? for how to verify. The patcher never installs itself into the game or runs in the background; it edits one file and exits.

Updating from an older Retrofit? 1.5.0 moves some of the patch's own code inside the executable, so a file patched by 1.4.x or earlier cannot be updated in place. The patcher recognises it, says so, and asks you to press Restore original first — then patch again. One extra click, once. Your settings are read back off the file either way, so nothing is lost.

How it works

The patcher operates on your own legally-owned copy of MFatigue.exe. It never distributes game code — it makes a backup, then patches your binary in place. This is how community patches have worked for decades.

• Works with both GOG and Steam — they ship the identical executable (see below).
• The game EXE exports 985 mangled C++ symbols, so functions were located by name — no guesswork.

⚠️ The EXE must stay named MFatigue.exe — the game refuses to launch under any other name. The patcher therefore patches in place (with a .bak backup), never emitting a renamed file.

Versions

Since 1.4.0 the unit budget is a slider with nine steps rather than four fixed versions:

Step	Unit budget
1.5×	12 MB soft cap (arena 15 MB)
2×	16 MB soft cap (arena 20 MB)
2.5×	20 MB soft cap (arena 25 MB)
3×	24 MB soft cap (arena 30 MB)
3.5×	28 MB soft cap (arena 35 MB)
4× ★	32 MB soft cap (arena 40 MB)
6×	48 MB soft cap (arena 60 MB)
8×	64 MB soft cap (arena 80 MB)
Maximum	120 MB soft cap (arena 128 MB)

★ recommended for 6+ players. Vanilla is 8 MB inside a 10 MB arena, so every step keeps that 80 % ratio; only Maximum pushes it higher.

The crew-name limit is a separate switch. Up to 1.3.x it was welded to Maximum, where choosing the biggest unit budget silently also changed how crews are named. The two limits come from unrelated places in the executable, and the interface now says so: tick Lift the ~50 crew-name limit to let each tier reuse its own names, which is what allows more than 50 crews alive at once — at the price of names repeating. Patched with Maximum before 1.4.0? Tick that box to keep what you had.

The memory soft cap is kept as a safety valve (blocks gracefully near real exhaustion instead of crashing) — just moved far above the artificial 8 MB wall.

Optional add-on: share vision with allies — allied units also lift your fog of war, and your allies keep their own sight while doing it. Up to 1.5.0 the option handed you their vision by taking it away from them, which left an allied AI effectively blind. Combinable with any step of the slider.

Cheats (optional)

A separate Cheats tab, layered on top of whatever you set above — nothing here is needed for the bug fixes, it's just for fun and experimenting. Everything is individually toggleable:

• No fog of war, Free building, Instant build, Unlimited high-tier crews (includes the crew-name limit, so the switch above is not needed alongside it).
• Free building and Instant build each carry their own Me only / All players (incl. AI) switch, so you can hand the AI one and keep the other to yourself.
• No fog of war needs no such switch: it lifts your fog and nobody else's. Until 1.5.0 it used the engine's own reveal call, which floods every player's visibility — the AI included — and left it permanently omniscient. It walks the fog grid itself now and writes only your view.
• Unit movement speed — a multiplier from 1.5x to 6x, for your units or for everyone. 6x is genuinely silly. (It sat on the Experimental tab until 1.5.0; it has been in the wild long enough not to belong there any more.) Before 1.5.0 a boosted unit could look further ahead than the engine had answers for, and steered on whatever happened to sit past the end of that list; that is fixed, so paths at the higher multipliers behave like the lower ones.
• Unlock combot parts of other factions — every faction's arms, legs and torsos, plus the three faction-specific superweapons. Build a Rimtech mech with a Neuropa plasma cannon and MilAgro legs. The AI actually uses unlocked parts too (its own build logic already salvages and researches enemy parts), so there's a scope switch here as well. All and None sit right in the frame; everything else is picked in a window that opens on a click. What you have selected is drawn as its own icons next to the count, so the loadout is visible without opening anything.

Loading an already-patched EXE restores every one of these settings in the interface, so re-patching never silently drops what you had.

Good to know (all working as intended, not bugs):

• Only cross-faction parts are unlocked. Your own faction's parts that require a specific building (e.g. a research center or AI facility) still need that building.
• Alien parts built during the prebuild phase must be re-researched at a research center afterwards.
• Unit and crew limits always apply to every player; part unlocks always apply to you (unless you flip the switch to all players).

Experimental (optional)

Its own tab, for things that reach further into the game than the rest. Read the warning at the top of it before ticking anything. Since 1.5.0 it holds one setting:

• Alternative cheats — Metal Fatigue ships a hidden cheat menu that was only ever made invisible: the buttons are still there, still wired to their hotkeys. This replaces what those two buttons do.

The control sequence, in a running game:

1. Esc to open the in-game menu.
2. Shift+C three times within two seconds. Nothing visible happens — the two hidden buttons are simply live from now on. Only the three presses are on a clock; once they have landed you can take as long as you like over the next step.
3. Hold a mouse button and press L or M.

All three steps again for every unit: spawning closes the menu, and opening it disarms the two buttons, so the sequence is one spawn long.

	no button	right button	left button
L	alien neutral enemy combot	alien neutral enemy tank	neutral enemy combot of random parts
M	the same, but yours	the same, but yours	the same, but yours

Everything appears where the camera is looking, so scroll there first — including into unexplored terrain, which the game is perfectly happy to place units in. The random combot draws a torso, a pair of legs and two arms from every faction's parts, so it can come out as anything.

Units spawned with L belong to the game's own alien slot: hostile to everyone, including you. They defend themselves but never advance on their own, because that slot has no AI behind it.

Two things to know before you tick it:

• The game's own instant-win and MetaJoules cheats are what this replaces. While it is on, they are gone. Not to be confused with Free building on the Cheats tab — that one is ours, it is a different patch entirely, and it works alongside the spawning without any conflict.
• Single player only. Spawned units are never sent over the network, so any multiplayer game will desync.
• There is a ceiling per level, not per living unit. The game hands out object slots and never takes them back when something dies, so spawning eventually stops for that owner and the console says Spawn limit reached. Losing your spawned units does not free it up; starting the next level does. The refusal is deliberate — spilling past that point corrupts the next player's units.

Music: Rimtech's missing soundtrack (optional)

Metal Fatigue shipped on two CDs. CD 1 held Rimtech's music, CD 2 held Mil-Agro's and Neuropa's. The game never told them apart in code — it asked the CD drive for a track number, and whichever disc sat in the tray decided whose music that was. The re-release ships only CD 2's audio, so Rimtech asks for the same numbers as Mil-Agro and gets Mil-Agro's music.

The Music tab fixes that by giving Rimtech ten track numbers of its own and copying your files into them. No game audio is included — the patcher ships none and links to no source. Supply the ten Rimtech tracks yourself, from your own CD 1 or wherever you can obtain them, as OGG Vorbis files (the game's audio layer reads nothing else).

• Import from a folder or a zip; the tracks are matched to their slots by playing time, not by file name, since every source names them differently.
• The list shows what is on disk right now, colour-coded: in use by the game, copied but not patched yet, or a length that does not fit its slot.
• Any track can be played back in the patcher, with a seek bar — handy when a source arrived in a different order and you need to sort it out. Rows can be moved with the arrow buttons.
• Remove imported music takes out only the ten files it added and restores the original track numbers. The game's own 22 tracks are never touched.
• Restore original does not delete your tracks. It puts the executable back, so the game plays its own music again, but the ten files stay where they are and the Music tab tells you they are ready — one Patch brings them back without importing them again. Use Remove imported music when you want the files gone as well.

The track order should match the CD, but only the exe's 16-byte table decides which numbers Rimtech asks for — so nothing breaks if a track sits one slot off; the wrong piece simply plays.

The workaround that circulates on the GOG and Steam forums is to overwrite tracks 03–12 — Mil-Agro's music — with Rimtech's, and then keep two MUSIC folders and swap them between sessions, because both factions ask the game for the same ten numbers. Renaming files cannot fix that; the numbers live in the executable. This patch changes the numbers instead, so all three factions keep their own music at the same time and none of the game's own audio is overwritten.

Is this safe?

Windows shows an "unknown publisher" warning. That is expected: the patcher is not code-signed, because a code-signing certificate costs several hundred euros a year — hard to justify for a free community patch. So instead of asking for trust, here is how to verify it:

1. Read the source. The whole patcher is in this repository under the GPL. The patch bytes and every offset live in patcher/PatchData.cs — nothing is hidden or obfuscated, deliberately.
2. Check the checksum. Every release ships SHA256SUMS.txt. Verify with Get-FileHash MetalFatigueRetrofitPatcher.exe -Algorithm SHA256 and compare.
3. Scan it. Upload the exe to VirusTotal — unsigned tools that write to other programs' files sometimes trigger heuristic flags.
4. Build it yourself. dotnet build -c Release builds the patcher from this source. Note that .NET stamps every build with its own build ID and source paths, so your binary will not be byte-identical to the released one — compare the source and the behaviour, not the hashes. The published checksums verify the download, not the build.

What the patcher actually does:

• Reads the registry to find your Steam/GOG install — read-only
• Reads and writes exactly one file: your MFatigue.exe, after creating MFatigue.exe.bak
• Writes one small text file (%ProgramData%\MetalFatiguePatcher\lastgame.txt) so the uninstaller can offer to restore the original
• Asks for administrator rights only because games often live under Program Files
• Makes no network connections, has no telemetry, installs no service and no auto-start. (The licence link simply opens your browser.)

It also refuses to touch anything it does not recognise: it verifies the file against the known build before patching, always patches from the verified backup, checks every byte it is about to overwrite, and re-reads the result afterwards to confirm.

Layout

• patcher/ — the GUI patcher (detect · choose settings · backup · patch · verify · restore)
• installer/ — Inno Setup script for the optional Setup.exe
• scripts/ — build and release helpers

Steam & GOG

The GOG and Steam MFatigue.exe are byte-identical (SHA256 26d428f1…, the Nightdive 2021 re-release, no SteamStub). The same patch offsets apply to both, and the patcher auto-detects either store.

Steam note: "Verify integrity of game files" will detect the patched EXE and re-download the original. That's expected — just re-run the patcher afterwards (your .bak also lets you restore). Steam does not re-verify on normal launch, so the patch persists.

Reporting a bug or an unsupported version

Open an issue →

• Something is broken — use Bug report, and paste the contents of the patcher's log box. That alone usually shows the cause.
• The patcher hit an unexpected error — it writes a file named MetalFatigueRetrofitPatcher-ErrorLog-<date>.txt next to its own exe and offers to open that folder. Attach it. It carries the version, your Windows build, what the patcher was working on and the full stack trace — everything the log box can't tell me. Your Windows user name is stripped out automatically.
• The patcher doesn't recognise your build — use Unsupported game version and include the file size and SHA-256 of your MFatigue.exe. Only the Nightdive re-release is supported so far.
• Nothing is broken, you just want to say something — use Feedback or idea. An idea, a rough edge, something that surprised you. The Feedback link in the patcher's own window opens that form with your version already filled in.

Worth reporting

• The patcher stops recognising a Steam or GOG copy. Usually means the game got an update and the executable changed — that affects everyone, so it's the most useful thing you can report.
• The game won't start, or crashes after patching, and doesn't on the unpatched original.
• "Restore original" doesn't bring the game back. Anything touching the backup matters most of all.
• A limit hits far earlier than the slider promises — production stalling like vanilla although you set 8×, for example.
• Combot production stops although Lift the ~50 crew-name limit is ticked, where names are supposed to be reused indefinitely.
• Multiplayer desyncs although every player ran the identical build. This is the least-tested area of the patch.
• "Share vision with allies" is enabled but nothing changes in a match with an ally.
• Wrong, garbled or missing text in any of the 10 languages, or text clipped inside the window.
• The patcher itself crashes, hangs, or shows an error you can't get past.

Things that are not bugs

All of these are expected — please check the list before opening an issue:

• Windows warns about an "unknown publisher", or antivirus flags the patcher. It isn't code-signed, and it writes into another program's file, which trips heuristics. How to verify it instead.
• Steam's "Verify integrity of game files" undoes the patch. Steam sees a modified EXE and re-downloads the original. Just run the patcher again.
• You still can't build more than ~50 combots at a time. The unit slider does not touch that cap on purpose — it comes from the crew-name list, which is its own switch. Tick Lift the ~50 crew-name limit if you want past it. Note the cap is on combots alive: losing one frees its name immediately.
• Unit production still stops eventually. The memory cap isn't removed, only moved far above the artificial 8 MB wall. It stays as a safety valve, so the game blocks gracefully instead of crashing.
• The framerate drops in huge battles. That's the engine, not the patch. A 2000-era RTS was never built for these unit counts and can't spread the work across modern multi-core CPUs, so faster hardware helps far less than you would expect. The patch lifted an artificial cap — it can't make an old engine scale.
• The patcher refuses your MFatigue.exe. Deliberate — it only touches builds it can positively identify. Report that as an unsupported version instead.
• You picked your country's flag in the patcher, but it still refuses your game. The flags only switch the patcher's own interface language. They have nothing to do with which build of the game is supported, and selecting one does not make the patcher work with a differently localised copy.
• You installed a fan translation and the patcher no longer recognises the game. The patcher only ever looks at MFatigue.exe. A translation that replaces just data files is completely fine; one that replaces the executable makes it a build the patcher doesn't know, so it refuses on purpose. In that case: restore the original EXE first (on Steam: Verify integrity of game files), patch that, then re-apply the translation — and note that if the translation replaces MFatigue.exe itself, it will overwrite the patch, so you can only have one or the other.
  • The widely used German language patch is unaffected — it was checked, and it only replaces files under TBD\ (mission data, text, cinematics). It never touches MFatigue.exe, so it works alongside this patcher in either order.
• Crews in spawned combots have no name, just "(1)". The engine names a crew as part of deploying a combot the ordinary way, and the spawn cheat does not go through that step. Cosmetic only — the combot itself is a normal unit.
• Multiplayer desyncs. Every player must run the exact same patch version. Differently patched EXEs will desync.
• Your allies don't see what you see. Share vision with allies only changes your view; each player has to enable it for themselves.
• The AI is brutally strong. If you set a cheat's scope to All players (incl. AI), or unlocked parts for all players, the AI gets those advantages too. That's what the switch does.
• The game won't start after you renamed the EXE. Metal Fatigue refuses to launch under any name other than MFatigue.exe. That's the game,