It could be a number of things, you might have a bad rom file or maybe you haven’t added the correct neo geo bios files to the emulators home directory?
I test my new roms on a PC first, that way the emulator you’re using in windows will tell you which files are missing from the ROM if the game fails to boot properly!
I’m playing neo games perfectly on my 4S with the arcade FBA (final burn alpha) core.[/quote]
the metal slug is for the psx,someone here already mentioned the same problem about restarting on ipad 4 when using psx core