One of the most dedicated projects is (Final Burn Alpha for DS). This is a standalone emulator specifically optimized for the 3DS. The developer, profi200, optimized the emulator specifically to run on the modest hardware of the 3DS.
Note: Do not search for pre-made "Neo Geo 3DS CIA" packs that claim to be all-in-one. They are often outdated. Learn to use RetroArch. neo geo 3ds cia
To install and play a Neo Geo CIA, your 3DS must be running (via boot9strap). Once that foundation is laid, you have two primary methods to play Neo Geo games: One of the most dedicated projects is (Final