The 1635 - Pokémon Fire Red (U)(Squirrels) ROM is widely considered the gold standard for the GBA hacking community. While it is essentially a "clean" dump of the original Pokémon FireRed Version 1.0 (US)
, its "exclusive" status comes from its role as the mandatory base for nearly every major ROM hack. Why "Squirrels" is the Gold Standard
In the world of Pokémon ROM hacking, not all FireRed files are created equal. The "Squirrels" version (named after the original scene group that dumped it) is specifically Version 1.0.
Version Compatibility: Later official revisions (like Version 1.1) changed internal memory addresses. Because of this, massive fan projects like Pokémon Unbound or Pokémon Radical Red only work when patched onto the Squirrels 1.0 ROM.
Engine Stability: Most hacking tools, such as Advance Map or PGE, are hardcoded to the 1.0 offsets found in the Squirrels dump. Core Gameplay & Features
If you play the "Squirrels" ROM without any patches, you are experiencing the definitive Gen III remake of the original Kanto journey. What's the difference between different roms?
While the "Squirrels" ROM is the base for many hacks that unlock all Pokémon, the original base game contains specific Pokémon that cannot be caught in LeafGreen.
The Ultimate Guide to Pokémon FireRed (U)(Squirrels) : Why it’s the Gold Standard for ROM Hacking
If you’ve ever ventured into the world of Pokémon ROM hacks, you’ve likely seen a very specific instruction: "Use the 1635 - Pokémon Fire Red (U)(Squirrels) ROM." 1635 pokemon fire red usquirrelsgba rom exclusive
To the uninitiated, this string of text looks like technical gibberish. But for seasoned hackers and players of fan-made masterpieces like Pokémon Unbound Radical Red
, it is the essential "base" that makes everything possible.
In this post, we’re breaking down what this ROM actually is, why it’s "exclusive" in the eyes of developers, and how it differs from the original 2004 cartridge release. What is the "Squirrels" ROM? "Squirrels"
refers to the specific individual or group who originally dumped (digitized) this version of Pokémon FireRed from a physical cartridge. In the emulation community, different "dumps" can have slight variations. The Squirrels version is widely considered the "cleanest rip"
, meaning it has no unwanted modifications or errors that could crash a game. Why is it "1635" or "1636"? You’ll often see it labeled as
. These are simply scene release numbers assigned by early rom-sharing groups to keep track of GBA titles. Version 1.0 vs 1.1: The most critical detail is that the Squirrels ROM is Version 1.0 of the US release. Compatibility:
Most major ROM hacks were built specifically using Version 1.0 as the foundation. If you try to patch a modern hack onto Version 1.1 (the version found in many later physical copies), the "memory addresses" won't match, and the game will likely fail to load. FireRed Version Exclusives
Whether you’re playing the "Squirrels" base or the original retail game, the core appeal remains the version-exclusive Pokémon. If you choose FireRed over LeafGreen, these are the critters you can find in the wild that your friends can’t: The 1635 - Pokémon Fire Red (U)(Squirrels) ROM
What's the difference between different roms? : r/PokemonROMhacks
In the ROM hacking community, this specific file is considered the "gold standard" because most major projects—like Radical Red Pokémon Unbound —are built using its exact memory addresses. The Kanto Collection: FireRed Version Exclusives
Because this ROM is a bit-perfect copy of the original 2004 retail game, it contains the standard FireRed version exclusives. To complete a Pokédex using this ROM, you would normally need to trade with a counterpart.
Below are the Pokémon you can find in the Squirrels (FireRed 1.0) ROM that are in LeafGreen: Pokémon FireRed and LeafGreen version exclusives list
Table_title: All Pokémon FireRed and LeafGreen version exclusives Table_content: header: | FIRERED | | LEAFGREEN | row: | FIRERED: Polygon.com
You're looking for a post related to Pokémon Fire Red, specifically a US version, and a mention of Squirrels in a GBA ROM exclusive. Here are a few possible posts:
Option 1: A fun fact about Squirrels in Pokémon Fire Red
"Hey fellow trainers! Did you know that in Pokémon Fire Red (US version), Squirrels are not actually a part of the game? However, if you're playing a GBA ROM hack that includes Squirrels as a Pokémon, it could be a fun twist on the classic game! Who else loves playing ROM hacks with exclusive features?" Copyright Infringement Pokémon Fire Red is copyrighted by
Option 2: A question about Pokémon Fire Red and Squirrels
"Hey gamers! I'm playing Pokémon Fire Red (US version) on my GBA, and I was wondering if there's a way to encounter Squirrels in the game. I know it's not an official part of the game, but I've heard rumors of ROM hacks that include Squirrels as a Pokémon. Has anyone tried a ROM hack with Squirrels in Pokémon Fire Red?"
Option 3: A post about a custom ROM with Squirrels
"Check out this awesome custom ROM for Pokémon Fire Red (US version) that includes Squirrels as a Pokémon! The ROM is exclusive to GBA and features a ton of new content, including Squirrels as a playable Pokémon. Has anyone else tried this ROM? What do you think of the new features?"
Copyright Infringement
Pokémon Fire Red is copyrighted by Nintendo, Game Freak, and The Pokémon Company. Distributing or promoting ROMs (copies of game cartridges) without permission violates copyright law, regardless of “exclusive” or “fan-made” claims.
Potential Malware / Security Risks
Strings like “usquirrelsgba” often appear on unofficial ROM sites known for bundling malware, trackers, or unwanted adware. Providing a report could inadvertently endorse unsafe practices.
Emulation vs. Piracy
While emulation itself can be legal (e.g., for homebrew or backups of legally owned games), downloading ROMs from the internet — especially altered ones — is not. “Exclusive” ROM hacks still require the base copyrighted game.
Subreddit & Community Rules
Most gaming subreddits (like r/PokemonROMhacks) ban direct links to ROMs or requests for them. Even discussing specific pirated ROMs by code name (“1635”) can violate policies.
While the ROM file itself is technically sound, the game it holds—Pokémon FireRed—is a masterpiece of the franchise.
The "1635 Pokémon Fire Red USquirrelsgba ROM" represents the creativity and passion of the Pokémon ROM hacking community. While specific details about this hack are limited, it undoubtedly offers players a unique alternative to the traditional Pokémon Fire Red experience. For enthusiasts of Pokémon and ROM hacks, exploring such projects can be a rewarding way to engage with the franchise from a new perspective. As with any ROM hack, players should ensure they download from reputable sources to avoid any potential risks associated with game modification.