GODZILLAULTRA

Everything starts from your own disc. Mine was checked against the Redump record for the US release (SLUS-20809) before anything was touched, and that original was never changed: every build is a copy.

The program

The game's program was loaded into a disassembler and mapped until each of its 15,720 functions had a name and a place. 5,009 of them were checked by reading the code itself; the rest are named from matching patterns and marked that way. The 1,541 commands of the game's own script language are named too.

The files

The disc holds one big data pack of 483 files, and inside them 87 kinds of file. 86 of them open in our own tools, and a tool only counts once it rebuilds every original file of its kind exactly, byte for byte, before it is trusted to change one. Movies are left out on purpose.

In the kit: the program map, the address map (751 findings, each with what it does and how it was checked), and a reader and writer for every file type.

With every file open, changing the game is changing data. Each kind of change has its own tool.

Scripts

Every menu, mode and mission is the game's own script language. Any of the 162 scripts decompiles to readable text and compiles back. The WAR ROOM modes, Living Tokyo, swimming and the threat levels are all script.Tools: script compiler, script checker, script command list

Cities

Everything in a city is a record: a class, a name, a position, a template. Move, add or remove any of them. Tokyo's 1,221 buildings, its bases and the navy were placed this way, district by district.Tools: city reader, city writer, unit adder

Monsters

A monster comes in with its own skeleton, mesh and moves, never stretched onto another monster's body. Stats, moves and every hit event are editable.Tools: port kit, bundle builder, skeleton, mesh and animation writers, move and stat editors

Textures

Every texture and palette can be swapped. The HD packs replace them while the game runs, without touching the disc.Tools: texture reader and writer

Everything else

Effects, cameras, sound, text, menus and collision each have their own reader and writer.Tools: effect, camera, sound, text, screen and collision editors

Code

Some changes need the program itself. Those are code patches the emulator applies at launch. Every word a patch changes is checked against the original first, and if one doesn't match, nothing is written. Each change is its own named switch.Tools: patch writer and checker

The limits

The 2004 game was built for a PS2. ULTRA moves its limits.

The test rig is the emulator in its own profile, hidden and muted, with tools around it:

• Every test starts from a saved scene in about three seconds, intros skipped.
• Buttons are pressed by script, so a test plays the same way every time.
• The game's memory is read while it runs: health, threat level, what has spawned.
• Pictures are taken on cue, and the emulator's log is checked for crashes.

A change moves through four steps. Built: its own checks pass. Mac-checked: a sweep of every map and mode it touches. Cleared: I've seen it. Confirmed: I've played it on the couch. Only the last one counts as working.

In the kit: the rig scripts for Save the Earth. Bring your own emulator and your own console's BIOS.

ULTRA runs on an Xbox Series S in Dev Mode through XBSX2, a PS2 emulator for Xbox. Dev Mode works on a free developer account.

• The disc goes over as a compressed image, with the code patch and the game's own settings beside it.
• Files go through the console's Device Portal, and each one is read back before it counts as there.
• The game runs with the emulator's most memory and its fastest CPU setting.
• Patches and settings load at launch: after a change, close the game fully and start it again.

Or skip the console: everything runs on PCSX2 on a computer.

I made GODZILLA ULTRA with an AI coding assistant, and I want to be plain about what that means.

The AI

Read the program and the files, wrote every tool in the kit, built the mods, and ran the tests on the Mac.

Me

Decided what the game should be, picked every change, and played every build on the couch. If something felt wrong there, it went back, however good the numbers looked.

Keeping it honest

Every claim is checked against the game itself: its code, its files, its memory while it runs, and marked as checked or not. A tool counts only when it rebuilds the original files exactly. Mistakes are corrected in writing, not hidden.

It isn't a shortcut around understanding the game. The understanding is the work, and it's all written down here.

I took a retail game and made it mine. You can do the same with yours, and you don't have to share my vision of it.

• The Build kit: the Save the Earth tools, the program map, the address map, notes on every file format, and the builders for every mod in ULTRA.
• The Play pack: one patch per mod, for your own disc.
• Bring your own disc. Nothing from the game is in either pack: no disc images, no game files, no code from the game.
• Start small: change one number in a script, rebuild, boot it. Then go further.

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