@Cederick said in Super Gameboy emulation?:
The Spaceworld demos where developed to run on super gameboy hardware since the gbc wasn't out around this time
In that case, the .gb file extension would be more appropriate, although as @edmaul69 mentioned, either should work. Keep in mind that .gb and .gbc both denote a certain type of ROM. Seeing as how the Super Gameboy never had a unique ROM type, I imagine that the .sgb extension is there to tell compatible emulators to load the Super Gameboy BIOS automatically. With lr-mgba, loading a .gb file with the Super Gameboy BIOS manually enabled should produce the same results.