An upgrade to Pokémon Crystal. Brings features and content up to date, and adds some original content.
Assembly
1,662
13,460 commits
updated Oct 10, 2026
This is a custom Pokémon game based on the Pokémon Crystal disassembly.
My goal is to create what the title says: an improved, polished version of Pokémon Crystal. It fixes bugs, takes into account the official game changes since 2001, and adds some new ideas of my own. Many features restore what was removed from R/B/Y, or original to HG/SS.
I've had vague plans to make a Pokémon game for years. I'm very impressed by the effort that's gone into disassembling Pokémon Crystal and making the code so well-organized. Thanks to making it open-source (and to the ROM hackers that inspired me), I'm finally making this game a reality.
There are many ways to create games but the way we work at Game Freak may be a little different from other companies. That is, we constantly change and tweak what we have come up with. To make a fun game even more fun and polish it up, we take what we have made and start thinking about it from scratch. And to make the game the most fun to play we make endless changes and tweaks no matter how long it takes. It may not be the best way, but I think these tweaks are important to make our games fun and better.
— Junichi Masuda, "HIDDEN POWER of masuda No. 7"
The current official release is v3.2.3 (the “Polished Crystal” release). It's fully playable from start to finish and includes major overhauls to gameplay, mechanics, and quality of life. A more detailed changelog is forthcoming, but you can find the major highlights below.
The previous official version was v3.1.1 (February 1, 2025).
If you have any questions about playing or patching, read the FAQ!
Below is a brief summary of the major changes and additions. A more detailed changelog will be released soon.
A full list of features is in FEATURES.md. Some highlights:
If you have questions or comments, please check or post on any of these sites. (Read the FAQ first if you have general questions!)
Additional resource:












57 followers · starred Jun 2021
32 followers · starred Feb 2023
453 followers · starred Feb 2021
94 followers · starred Mar 2026
An upgrade to Pokémon Crystal. Brings features and content up to date, and adds some original content.
Assembly
1,662
13,460 commits
updated Oct 10, 2026
This is a custom Pokémon game based on the Pokémon Crystal disassembly.
My goal is to create what the title says: an improved, polished version of Pokémon Crystal. It fixes bugs, takes into account the official game changes since 2001, and adds some new ideas of my own. Many features restore what was removed from R/B/Y, or original to HG/SS.
I've had vague plans to make a Pokémon game for years. I'm very impressed by the effort that's gone into disassembling Pokémon Crystal and making the code so well-organized. Thanks to making it open-source (and to the ROM hackers that inspired me), I'm finally making this game a reality.
There are many ways to create games but the way we work at Game Freak may be a little different from other companies. That is, we constantly change and tweak what we have come up with. To make a fun game even more fun and polish it up, we take what we have made and start thinking about it from scratch. And to make the game the most fun to play we make endless changes and tweaks no matter how long it takes. It may not be the best way, but I think these tweaks are important to make our games fun and better.
— Junichi Masuda, "HIDDEN POWER of masuda No. 7"
The current official release is v3.2.3 (the “Polished Crystal” release). It's fully playable from start to finish and includes major overhauls to gameplay, mechanics, and quality of life. A more detailed changelog is forthcoming, but you can find the major highlights below.
The previous official version was v3.1.1 (February 1, 2025).
If you have any questions about playing or patching, read the FAQ!
Below is a brief summary of the major changes and additions. A more detailed changelog will be released soon.
A full list of features is in FEATURES.md. Some highlights:
If you have questions or comments, please check or post on any of these sites. (Read the FAQ first if you have general questions!)
Additional resource:












57 followers · starred Jun 2021
32 followers · starred Feb 2023
453 followers · starred Feb 2021
94 followers · starred Mar 2026