There's a lot of easy ways to play Game Boy ROMs, if you're so inclined. You can play them on an emulator: nearly every platform under the sun has a perfectly capable Game Boy emulator available for it. I have Game Boy emulators installed on my laptop, PSP, Nintendo DS, GameBoy Advance and cellular phone. Of all my gadgetry, only my watch stubbornly refuses to play Link's Awakening, but oh... give it time.
So you could do that. Or you could just carve up your own circuit board then hack, splice and solder a floppy drive to your old-school Game Boy Color, allowing it to read ROMs directly from a 3.5" disk. You know. Whatever's easiest.
Even better? The French modder who dreamed this up touts "portability" as a bullet point.
Sheer, stubborn, wild-eyed hacker insanity... awesome to behold, worthy of our incredulous applause.