Would you maybe elaborate on how you succeeded on this? Do we need th.at 3ds homebrew stuff i hear people talk about? Do we need to do anything specific based on the mod? does it run well? etc etc.
Also it might be mostly okay but how legal is this anyway? I remember it being far from ok on the wii.
It runs on Libretro NXEngine which is distributed with Libretro, a open source emulator package avalable for many platforms including PC, Mac, Linux, Wii and yes the 3DS. It is GPLv3 licenced. You do need to be able to have user mode homebrew access to run NXEngine/Libretro on the 3DS. NXEngine can NOT run ASM mods without modification to NXEngine's source itself (which is perfectly legal to modify and redistribute). NXEngine contains NO Pixel or Nicalis code by it self. Mods do need to be modified if they use ANY ASM due to the Wavetable being :b:roke (otherwise you will hear
n x w a v e which is caused by incorrect wavetable). Also, ORGs need to be put in the orgs directory manually, same with sound effects. NX needs to be modified if any maps were created or deleted or it will error out and crash while extracting. Some issues I had when porting #4 was that the TSC would freeze the game and lock keyboard and run a effect which wouldnt end. I fixed this by creating a save file that starts out at the beginning of the game by saving in Kings and resetting so i could have a more stable enviorment to warp to map 12 and save there. NX has to be modified for doing much more than running "first mod" like mods (same map list, no asm, same sfx, etc.) So NX would have to be modified for each mod and recompiled. It runs at a solid 60 FPS. I did get permission from VB to put the assets in a zip with NXEngine included. I didn't redistribute the source of NX because I did not modify the source. Also Kings had a weird issue with animation and the timer didn't show up and 1 HP wasn't set because that was done with ASM. Also, title screens are not gonna look right unless they are optimised for a scrolling cloud background.
EDIT: It is perfectly legal to redistribute PC CaveStory files (NOT +).
EDIT 2: Including a mod with nx is also legal as long as permission is gotten from the author and the source for the modified NXEngine is included and/or publicly avalable. Linux does this sort of with "binary blob" drivers which are nonfree/closed source.
EDIT 3: NX its self is legal. Nicalis can't DCMA someone for using/hosting NXEngine as they don't own the copyright to NXEngine. It's like if Nintendo sent a C&D to a emulator developer or if Broadcom sent a C&D to QEMU for their qemu-system-arm package which emulates ARM CPUs including Broadcom's bcm2835 SoC. They can't. Another example would be if Microsoft sued Apache over OpenOffice being able to open .DOC and .DOCX files. MSFT can't sue. Same with Nicalis, Nicalis can't patent the idea of a Cave Story Engine, only their implementation of it. A while ago, there was a Flash version of NXEngine, this WAS illegal but not for the reasons you might think. It was illegal due to it making the source code available. However, Nicalis had no legal authority to take it down. Only the creator of NXEngine does. And no, Cave Story is no longer a trademark and hasn't been since June 5, 2009. According to the trademark office, Nicalis abandoned the trademark (Trademark #77526825)