How to Play

Epsilon Emerald is distributed only in patch form—that is, in order to play the actual GBA ROM, you’ll first need to apply the patch to a clean, vanilla copy of an English Pokémon Emerald ROM.

Thanks to byuu for creating the BPS patch format <3

Requirements

You will need a clean copy of an English base Pokémon Emerald ROM.

I can’t provide or tell you where to get this; sharing ROMs is forbidden and legally dubious.

If you Google around though, you can easily find one, or dump your own Emerald cartridge if you have one.

Instructions

Load your base Emerald ROM into the patcher and make sure it shows green. The SHA-1 hash must be exactly f3ae088181bf583e55daf962a92bb46f4f1d07b7. The patcher will tell you if it’s correct or not.
Select your version of Epsilon Emerald, if applicable, and click Apply patch.
You’ll download a file named pokeepsilon.gba; this is your ROM!

Note: Do not use an already existing pokeepsilon.gba here; each time, it must be a base Emerald ROM.

To upgrade, just replace your old pokeepsilon.gba with the new one; your save data will carry over!

Recommendations

Once you have your ROM, there are a few ways to play:

For PC: I reccommend mGBA: https://mgba.io/
For Android: I’ve heard good things about PizzaBoy and GBA.emu
For iOS: Delta seems to be the go-to: https://deltaemulator.com/

Note: !! Do not use any VBA emulator or its derivatives! VBA is quite inaccurate and you may run into various issues, which are beyond my scope to fix because of how outdated it is.

You can also play on a Nintendo 3DS, either by injecting the ROM as a .cia with the New Super Ultimate Injector or baremetal with open_agb_firm.

And of course, you can play on original GBA hardware, if you can get the ROM onto a suitable cartridge: GBA, GBA SP, GB Micro, GameBoy Player, etc.

Note: If, when flashing to a flashcart, you receive an error to the effect of “The ROM file you have selected will not boot on actual hardware due to invalid boot logo data”, click “Continue without fixing”; the flasher may be unaware that the GBA ROM header is allowed to differ in 1 byte to enable debugging behavior (which I use to show a crash screen).

For Nerds

I sign all binaries of Epsilon Emerald with my public PGP key, which you can import from my GitHub:

curl -s https://github.com/aarant.gpg | gpg --import

You can then verify the ROM was built by yours truly, either with this signature or extract the one embedded in the BPS patch manifest:

gpg --verify pokeepsilon.gba.sig

Patcher

ROM file:

CRC32:

SHA-1:

ROM:

Patch file:

Description:

ROM requirements: