AVAILABLE NOW · ARTWORK
ThunderYellow cover art
Download the original fan-project cover artwork as a 900 × 900 JPG. The artwork can be saved on an iPhone or shared as a link.
Unofficial fan artwork, not an authorized Nintendo or ESRB product.
Game release status & downloads
First public release coming later
Pokemon: ThunderYellow Version (2026 Special Edition) has not been publicly released. The project is being developed and tested. A game download will appear here once a public release package is actually prepared and verified.
First Public Release · In DevelopmentWhat's available now
NOT RELEASED · GAME
ThunderYellow — first public game release
The first public edition is in development. We have not published a playable ThunderYellow release yet.
The first-release patch still requires verification and gameplay testing. No release date has been announced.
Why no download button? An earlier page incorrectly offered an update that only worked with a private development build. It was not a usable public first release, so that offer has been withdrawn.
Ready for the first release
Check your own LeafGreen Rev 1 game
Use our browser installer to confirm your Pokémon LeafGreen (USA), Rev 1 / 1.1 file matches the supported original. When the ThunderYellow release patch is verified and published, it will generate the complete playable .gba on your device. No ROM upload and no manual patching.
What the first release will need
The public experience is designed around a local browser installer: players supply their own legitimately obtained Pokémon LeafGreen USA Rev 1 game, and receive a new ThunderYellow .gba after a verified first-release patch is published. This site does not distribute the Nintendo ROM.
01 / FINISH TESTING
Check gameplay
Validate follower behavior, major encounters, legendary event access, saving, and compatibility on the intended build.
02 / VERIFY THE PATCH
Build a clean-base release
Generate a patch against the specifically supported original LeafGreen revision; verify the exact base-file checksum and that patching reproduces the intended game.
03 / PUBLISH
Release with instructions
When tested and approved, post the patch, installation steps, version notes, file hashes, and known issues in this download center and announce the release on Reddit.
When released: iPhone or Android
You will use the same finished ThunderYellow .gba game on both phones. Install an emulator on your device, then import the complete game created by our browser installer.
APPLE · IOS & IPADOS
Delta Game Emulator
Get Delta from the App Store and import your ThunderYellow .gba from Files.
ANDROID
Pizza Boy A Basic
Get Pizza Boy A Basic from Google Play and load the finished .gba from Downloads. RetroArch is another option.
Legal ROM use
ROM use & legal disclaimer: Emulators may technically load ROM files obtained from different sources, but that does not mean every download is authorized. ThunderYellow does not provide, link to, or endorse unauthorized copies of commercial games. We recommend using a lawfully obtained original Game Boy Advance cartridge and making your own personal backup where permitted by applicable law. Rules vary by location; you are responsible for ensuring you have permission to use the game file you select.
Questions
Has ThunderYellow already been released?
No. We are preparing the first public edition. Internal development builds are not public releases.
Can I download the game today?
No public ThunderYellow game version has shipped yet. Cover art is available now, and you can verify your own LeafGreen Rev 1 ROM with the browser installer.
Where can I find the exact LeafGreen ROM?
We do not host or link to unauthorized ROM downloads. You can look for an authentic secondhand LeafGreen GBA cartridge, make your own .gba backup with a suitable reader such as the GB Operator, then confirm the exact USA Rev 1 fingerprint in our installer. Not every LeafGreen cartridge is the supported revision. See the device and sourcing guide.
How far along is development?
Specific gameplay systems have passed internal checks, but full regression testing, packaging and compatibility checks are still required before the first public release.
Will the website distribute a complete .gba ROM?
The website will generate a complete ThunderYellow .gba locally from the user-supplied compatible LeafGreen original and a verified game patch when the first release is approved. It will not host or distribute Nintendo's original ROM.
Follow development updates
Join the project's Reddit community or submit reproducible test issues through technical support.