Nebula 1.0.0

Nebula runs Super Mario Galaxy natively on Windows. Setup compiles the game from your own copy of the USA release (RMGE01, revision 0); the download contains no Nintendo code or assets.

Install

1. Download Nebula-Setup.exe below and run it. The file is not code-signed, so Windows SmartScreen shows "Unknown publisher": choose More info, then Run anyway.
2. Select your copy of the game (ISO, RVZ or extracted folder) and choose Install. Setup downloads a compiler and builds the game modules, which takes a few minutes.
3. Start Nebula from the Start menu.

Saves and settings from earlier versions are kept. Installs of a 0.1.1 beta do not offer this release as an update; run the new Setup once.

Changes since 0.1.1-beta.4

Performance

• The game's code runs as native x86-64. Guest registers stay in host registers between calls, calls follow the PowerPC calling convention, floating point uses host instructions, and the most-run functions are linked together, which helps most on CPUs with smaller caches.
• The game's threads run on a cooperative scheduler instead of separate host threads.
• New materials draw with general shaders while their specialized pipelines compile in the background, textures decode on worker threads, and Setup installs a shader cache, which removes most first-visit stutter.
• Frame-rate overlays (NVIDIA, Steam, Xbox Game Bar) show the game's actual frame rate, and the display stays on while Nebula is in front.

Controls

• Xbox controllers, the Switch Pro Controller and the Switch 2 Pro Controller (USB), with remappable buttons in Nebula Settings and in the in-game settings menu.
• Switch controllers point with the gyro. The pointer hides after 4 seconds without movement and returns with R, as in the Switch release.
• Tilt steers the Star Ball and ray surfing.
• Vibration follows the game, with on/off and a strength setting from 10 to 100 %.

Display and graphics

• Windowed or borderless fullscreen; borderless at the screen's resolution is the default. In windowed mode the window sizes match the chosen aspect ratio.
• Aspect ratios from 4:3 to 32:9, with the game's menus and HUD placed for each.
• Internal resolution up to 16x, adjustable while playing.
• Optional SMAA or FXAA, AMD FidelityFX FSR 1 upscaling with sharpening, anisotropic filtering, generated mipmaps, per-pixel lighting and a longer draw distance. All are off by default.
• In-game settings menu: F1, View + Menu (Xbox) or Minus + Plus (Switch).

Fixes

• First-person views and cutscenes no longer show a small copy of the scene in the top-left corner.
• A long system stall makes the audio skip instead of stopping the game.
• Exclusive fullscreen is no longer offered: it could freeze when Windows showed something over the game. A saved exclusive fullscreen setting opens borderless.

Requirements

• Super Mario Galaxy, USA (RMGE01), revision 0, as an ISO, RVZ or extracted folder
• Windows 10 (version 1803 or newer) or Windows 11, 64-bit, with a Direct3D 12 GPU
• 8 GB of RAM; 16 GB of free disk space during installation, about 5.5 GB afterwards
• An internet connection during installation

The least powerful system tested so far, an Intel Core Ultra 9 185H with its integrated graphics and 16 GB of RAM, runs the game at a locked 60 FPS at 1440p (16:10).

Known issues

• Heavy background CPU load can make the audio skip.
• Some areas, for example the Gateway Galaxy, drop below 60 FPS on weaker CPUs.
• Some lighting and bloom effects in the Comet Observatory differ from the original.

Nebula is an independent project and is not affiliated with Nintendo. The README explains how it works and how it was built. Report problems on the issue tracker.

Nebula 0.1.1 Beta 4

Nebula Beta 4 packages the accumulated runtime performance, graphics, audio and input fixes, with an installer that can reuse or relink the compiled game during updates.

Install or update

Download Nebula-Beta-Setup.exe and run it. It offers Install on a fresh machine and Update for an older registered installation. Uninstall and Restore the previous version remain available. Saves and settings are preserved by default.

The public engine, renderer, launcher, recompiler and arithmetic libraries are already built and embedded in this EXE. Users do not build the non-game runtime. First installation compiles only the game-derived modules from the user's own supported game copy.

Updates stage a complete version, validate it, then switch over while retaining the previous version for rollback. They prefer compatible module reuse, then relinking retained compiled objects when public libraries change. Recompilation is the last resort when objects are missing/unusable or the module ABI is incompatible. New installations retain a private object cache for future relinks. No generated Wii source was hand-edited.

Included fixes

• CPU snapshot lookup, paired arithmetic, FIFO/dependency processing, BP metadata and DSP polling improvements; checked host-only link optimization.
• Shader-cache persistence and completion-wakeup fixes, actual texture allocation budgeting, persistent EFB descriptors and exact RGBA8 identity copies.
• Asynchronous audio endpoint recovery, recovery during queue backpressure, replay pointer metadata and cached movie/pointer hook correctness.
• Previous Observatory/IOS bounds and interrupt fixes, with module ABI validation before updates.

No recording, Lightweight recording and Detailed recording remain available. Use Lightweight for a five-minute playtest; after exiting, open diagnostics and send the recording ZIP with your settings and the problem location.

Validation and limits

Core/CLI tests: 416 + 31 passing. Native host, interrupt and cached-call checks pass. Actual game/Home/DSP objects passed preservation/relink tests with zero compiler calls and unchanged object hashes. Corrupt retained objects are rejected. The same C++ runtime sources completed a base-resolution Observatory smoke run with normal exit. Its short sample was 59.696 new FPS, not a sustained-60 result; a 70 ms audio-starvation episode occurred outside that interval.

Lower-end acceptance, all-scene sustained 60 FPS, extreme-resolution performance and matched Galaxy superiority over Dolphin remain unverified. Start laptop testing at 1x / actual EFB 640x528. This is a beta checkpoint, not a claim that every slowdown or bug is solved.

The installer uses the portable SSE2 x64 baseline. PUBLIC-PAYLOAD-SHA256.txt identifies its embedded runtime, launcher and libraries. The local portable playtest uses those same runtime and launcher bytes. Public assets contain no game-derived modules, game content, personal saves or driver pipeline caches. The .sig is Nebula's updater signature; the EXE is not Authenticode signed.

Nebula 0.1.1 Beta 3

Nebula 0.1.1 Beta 3 fixes the reproduced crash when entering the Terrace in the Comet Observatory. It also corrects a render-completion timeout and checks valid memory ranges for thread wakeup stacks. Previous performance and Mario model fixes are retained.

Install and play

1. Download Nebula-Beta-0.1.1-beta.3-win64.zip and extract the whole folder to a new location.
2. Open Nebula.exe and click Play. Select game.pak from your existing installation if prompted.

This portable build uses your existing saves and shader cache. Progress saves normally, and a backup is made before the first launch. Keep your previous installation. Update the entire portable folder; do not replace an older installation's runtime EXE alone.

Optional recording

• No recording: normal play; this is the default.
• Lightweight recording: basic performance logs.
• Detailed recording: additional timing for investigating problems; it can reduce performance.

After closing the game, use Open diagnostics to find recording ZIPs. If a scene crashes or slows down, record a short reproduction and describe the location and your settings.

Sustained performance on lower-end PCs remains under investigation. This update does not establish 60 FPS on low-end hardware or a performance advantage over Dolphin. Other Observatory scenes, targeting responsiveness and full graphics/audio behavior still require testing.

Nebula 0.1.1 Beta 2

Nebula 0.1.1 Beta 2 includes CPU and renderer performance improvements and a fix for Mario's distorted model.

Play

1. Download Nebula-Beta-0.1.1-beta.2-win64.zip and extract the whole folder to a new location.
2. Open Nebula.exe, choose your settings and click Play. If needed, select game.pak from your existing installation.

This portable build uses the same saves as the regular installer. Progress is saved normally. Existing saves and caches are backed up before the first launch. Keep your existing installation; do not replace its EXE alone.

Recording

• No recording (default): ordinary play.
• Lightweight recording: basic performance and diagnostic logs.
• Detailed recording: additional CPU/renderer and GPU timing; this may reduce performance.

Recordings are saved under Open diagnostics as ZIP files after closing the game.

For lower GPU load, select 480p internal resolution. Increase it if performance allows. If you encounter a problem, use Detailed recording for a short reproduction and send the ZIP with a description.

Castle-area slowdown and IR responsiveness remain under investigation. Performance on lower-end PCs still needs testing.

Nebula 0.1.0-preview.2

Nebula 0.1.0-preview.2

Setup now takes a few minutes instead of over an hour.

Download Nebula-Setup.exe. (Nebula-Setup.exe.sig is used by the updater.)

Changes

• The game compiles with clang instead of MSVC.
• The runtime ships prebuilt inside Setup.
• The compiler downloads while your game is extracted.
• Needs 8 GB RAM (was 16) and 16 GB free disk space (was 22).

Requirements

Super Mario Galaxy USA (RMGE01, revision 0) as ISO, RVZ or extracted folder;
Windows 10/11 64-bit; a DirectX 12 GPU; internet for the first install.

Updating from preview.1: use Check for updates.

Nebula 0.1.0-preview.1 (development preview)

Nebula builds an unofficial native Windows x64 version of Super Mario
Galaxy on your PC from your own copy of the game. Only the North American
release, revision 0 (RMGE01, main.dol SHA-1
9a71008ae1ee9010e267fa67d1f0b0d4f0e895dd) is supported. This is a
development preview: locked 60 FPS and complete game compatibility are not
established.

Download

Nebula-Setup.exe is the only file you need. It is not code-signed,
so Windows SmartScreen may warn on first run. (Nebula-Setup.exe.sig is used
by Nebula's own updater; you don't need to download it.)

Setup asks for your ISO, RVZ or extracted game folder, then downloads
Microsoft's C++ compiler and Windows SDK (about 400 MB, hash-checked, under
the Visual Studio Build Tools license you accept in Setup), CMake and Ninja,
and this release's exact source from this repository. It then recompiles and
compiles the game locally. Nothing from your game is uploaded or downloaded.

Requirements: Windows 10/11 x64, a DirectX 12 GPU, 16 GB RAM (32 GB
recommended), 22 GB free on an NTFS drive during setup (about 7 GB
afterwards), and an internet connection. Compiling took 71 minutes on a
16-core test PC; expect longer on smaller PCs.

What's included

• Native D3D12 renderer with widescreen (4:3 to 32:9), HUD and Home Menu
  layout repairs, selective bloom and display-copy filtering.
• Internal resolution from native 480 up to 16x (10240×8448), e.g. 32:9 at
  2160p.
• Mouse as the Wii Remote pointer, keyboard and XInput controls.
• Native THP movie playback and native recompiled DSP audio.
• Install, repair, signed online updates that keep the previous version for
  rollback, and uninstall that keeps your saves and settings.
• Import of existing GalaxyRecomp saves (alternate data streams included).
• Optional per-session diagnostics (off by default).

Tested in this release

• Fresh install from an extracted folder into a path with spaces, first
  launch, file select with the mouse pointer, new save file, gameplay and
  Home Menu, normal exit.
• ISO and RVZ inputs (images rebuilt from the tester's own dump, not retail
  images): extraction and generation identical to the folder input.
• Unsupported games rejected before any work; interrupted installs recovered.
• Compatible update (modules reused), update requiring regeneration (rebuilt
  from retained game files), rollback and uninstall.
• 12x internal resolution at 32:9.
• Not yet done at publication: an install on a clean Windows machine (Windows
  Sandbox). All tests above ran on the development PC, using only the
  toolchain Setup downloads.
• The setup's download of this release's source from GitHub was checked
  file-by-file against the manifest built into the setup (701 of 701 files).
• Online update discovery against this release: an older updater found it,
  downloaded it and verified its signature; a tampered signature was rejected.

Known limitations

• 60 FPS is not sustained in every scene; some areas drop sharply.
• Full-game compatibility is not verified.
• Heavy background CPU load can stop the game with an audio deadline error.
• Native THP movies were not re-run in this exact build (sources identical
  to the qualified build in which they played).
• Only RMGE01 revision 0 is supported.

Source and licenses

GPL-3.0-only. The complete corresponding source is this repository at tag
v0.1.0-preview.1; Setup downloads exactly that revision and verifies every
file. See README.md, THIRD-PARTY-NOTICES.md and docs/PROVENANCE.md.
Not affiliated with or endorsed by Nintendo. AI tools were used in
developing this project; see the README.