The Best Game Boy and GBC Pokemon ROM Hacks

Crystal Clear, by ShockSlayer, is the boldest GBC hack around. You can start in any town in Johto or Kanto, choose from 24 starters and take on 16 gyms in any order, with leaders scaling to your badge count. A new Elite Four, all 251 Pokemon, a follower, buyable houses and Stadium 2-style touches round it out. It has been developed since 2017, saves carry over between updates and the official download is distributed through the author's Discord.

Polished Crystal is what Crystal might look like with modern Game Freak polish. Rangi42 and team built it on the pokecrystal disassembly, adding 289 species, regional variants, 73 new moves, a physical/special split and mechanics from Gens 6 to 9. A faithful build keeps closer to the original if you prefer. v3.2.0 from October 2025 marked completion, and v3.2.3 followed as a hotfix in December. It is the best way to replay Johto with depth.

Prism has one of the most dramatic histories in ROM hacking: Koolboyman's project received a cease and desist in December 2016, days before its planned release, and leaked anyway. RainbowDevs later took over development. You explore Naljo as Lance's child, meet new types like Gas and Sound, and try mining and jewel crafting. v0.95 build 0254 is the current release, with up to 20 badges and a Rijon post-game. It remains technically a beta, but it is huge.

Crystal Legacy keeps Johto exactly as you remember it but fixes the pacing. TheSmithPlays' team makes Chuck, Pryce and Jasmine scale to your fifth, sixth and seventh badge, gives Kanto its own league-style progression and makes every legendary, the GS Ball event and Ruins of Alph fossils available. There are no new Pokemon or physical/special split; the point is a cleaner Crystal. v1.3.1 from August 2024 is complete and includes a Hardcore mode.

Pokemon Orange, by Pia Carrot, sends you through the Orange Archipelago from the anime's second season. It won PokeCommunity's Hack of the Year in 2017. Expect Orange Islands and Alolan variants, a Crystal Onix, Pinkan Berries and events for Ho-Oh and Marshadow. A Regular build and a physical/special split build are both available. Development has moved to a rewrite, so the current build is finished but will not receive more updates.

Pokemon Brown was first released in 2004 and is often credited as the first hack to replace Kanto with an original region and story. RainbowDevs rebuilt it for its 20th anniversary: Rijon's maps are overhauled, the roster reaches 231 Pokemon, extra types such as Wind and Sound are used properly, and the battle engine gains a physical/special split. v6.1.2 from December 2024 is the latest. Play it before Prism to see where the story starts.

Yellow Legacy is the prequel to Crystal Legacy and applies the same thinking to Kanto. Ghost becomes a real counter to Psychic, Bug no longer beats Poison, broken moves like Focus Energy work and all 151 Pokemon can be caught in one save, with trade evolutions moved to level-up. Running shoes, a better bag and a Move Reminder improve daily play. An optional Hard Mode adds Set style, no battle items and level caps. v1.0.10 is current.

PureRGB, by Vortyne, is a purist's enhancement: it refuses to add anything from later generations, no new Pokemon, moves or type matchups, and instead makes the original 151 more useful. Movesets and stats are rebalanced, some species get secondary types (Ninetales becomes Fire/Ghost, and you can revert any of them), and new areas like Cinnabar Volcano appear. A custom Poke Ball designer and a Move Dex are surprisingly deep. v2.7.6 from September 2026 ships PureRed, PureBlue and PureGreen patches.

Shin Pokemon, by jojobear13, imagines what the 2016 Virtual Console release of Gen 1 could have been. It is mostly vanilla, but it fixes engine bugs and oversights, improves trainer AI and adds optional quality-of-life features explained in a separate player guide. A Lite branch keeps only the fixes and AI. Patches are BPS files for the US Red and Blue ROMs, and Green and Japanese Red variants are included. Version 1.25.0 arrived in October 2025.