I am trying to play Rampage on my New 3DS. I downloaded the Retroarch CIA pack and installed the libretro MAME 2003 core, and used it to open the zip archive containing the arcade ROMs. It suggested the MAME 2003 0.78 core. The game’s title screen comes up fairly quickly and I can use SELECT to add credits and START to begin the game, but the frame rate is only around 20 FPS, very slow and jerky, and the audio is slowed down, time stretched and stutters. Is there a setting I can change which could improve performance? Or a different core I could use?