Because the game is rare, fake ROMs (riddled with malware or broken save states) circulate. A genuine Four Swords Anniversary Edition ROM will have the following fingerprints:

If you want, I can:

This article explores why this version is so coveted, what makes the ROM unique compared to the original Game Boy Advance (GBA) release, and the technical hurdles of playing it today. What Makes the Anniversary Edition "Exclusive"?

Legal and ethical context

While technically a DSiWare remaster rather than a traditional ROM, this version contains significant content not found in the GBA original:

is an enhanced remaster of the original Game Boy Advance (GBA) multiplayer title, originally released for a limited time on DSiWare and the Nintendo 3DS eShop to celebrate the series' 25th anniversary.