This is a port of the popular Binding of Isaac Rebirth mod The Binding of Undertale! All credits go to the original author, I simply changed somethings to make it work on N3DS and selfishly slapped my amazing username on the title screen. If you have any issues or requests for other Binding of Isaac mods, please let me know! SCREENSHOTS Warning: Spoilers inside! DOWNLOAD Warning: Spoilers inside! US Version EU Version INSTALLATION Warning: Spoilers inside! CIA Recompile (Recommended) - Download and install PackHack (https://github.com/Asia81/HackingToolkit3DS/releases) - Take your decrypted Binding of Isaac Rebirth CIA and put it in the same folder as PackHack - Launch 'HackingToolkit3DS' and extract the contents of the CIA (ce for CIA extract, you don't need to decompress the code.bin) - You should now have 'ExtractedRomFS' folder and a bunch of other files - Extract the 'resources' folder from 'luma/titles/titleID/romfs/' within the zip and place it in 'ExtractedRomFS' (Overwrite everything) - Launch 'HackingToolkit3DS' and enter 'cr' to recompile the CIA, choose the name, enter '3' for minor version and '0' for micro version (if you don't enter the version, it will always ask you to update and fail) Recompiling as a CIA actually saves 58MB as it replaces some of the original music Luma LayeredFS (Has performance issues) - Extract 'luma' folder to the root of your microSD - Hold 'Select' while powering on your N3DS - Ensure 'Game Patching' is enabled in Luma's configuration - To remove, delete '000400000f700800' for US and '000400000f700900' for EU from 'microSD:/luma/titles' CHANGES Warning: Spoilers inside! rev.1 - Fixed the white floors when recompiled as a .cia (I think) - Included changes.txt and readme.txt - Reduced music to 64kbps saving over 20 MB - Removed .xml files from /romfs which were included by mistake - Fixed formatting of players.xml to make it easier to read - Overall filesize reduced from 65.9 MB on disk / 57.7 MB zipped to 43.2 MB on disk / 35.3 MB zipped EXTRA INFO Warning: Spoilers inside! I've obviously made some progress with Binding of Isaac Rebirth mods on the 3DS and have managed to get The Binding of Undertale to work. There are still some obvious slowdowns due to loading, although I do feel there could be an issue with Luma's LayeredFS and this game as it works fine if you recompile the mods into a CIA. I guess I'll open an issue over there and hopefully they can find something. It seems there are 53 3DS specific files and even more contained in animations.b. As you can see, the majority of them are graphics, but there are a couple of xml. Those xml and others which have the same name across all versions require editing to work on the 3DS version. I haven't properly documented any of this, but it's pretty easy to figure out simply by comparing against what you find within BoI Rebirth's ROMFS. I haven't tried anything that changes .anim from animation.b yet, they're essentially .xml files and may need editing as well, but we'll find out later. In my research, I found I'm certainly not the first person to try or successfully do this. The 3DS specific contents of animation.b have been extracted and documented thanks to /u/jerbear64 and /u/dedChar had also ported, The Agony of Isaac. They had reported that upon adding additional things into the game, it appeared to run out of memory and enemies would be invisible. I haven't fully play tested The Binding of Undertale, but in my short runs I haven't experienced this. So anyway, that's all the babbling I have for now. Enjoy!