It's not a 32/64 bit issue. Spooky Remix has not been officially added to MAME. The developer swapped the game into the program space of the Donkey Kong II: Jumpman Returns version 1.1 ROM (dkongx11). So in order to run Spooky, you need a version of MAME that supports dkongx11, which would be 0.140 or higher.
It will be listed in frontends with the description "Donkey Kong II: Jumpman Returns (hack, V1.1)," and (depending on what you're using for a frontend) actually may not be listed, or run at all, since the ROM audit will fail. The only sure way to get the game to work is to use the command line.