"The game runs slow/glitchy." Solution: This is rarely the ROM's fault. It is usually your emulator settings. Try changing the video driver (OpenGL to Vulkan) or disabling "VSync."
For those looking to explore the technical or legal side of retro gaming beyond this site, communities like r/RetroArch provide information on how to legally purchase and extract ROMs from official sources like Steam or GOG . Romspedia (@romspedia) wwwromspediacom best