It sounds like you’re looking for a review or overview of the concept of “all 3DS ROMs” — likely referring to the complete library of Nintendo 3DS game ROMs (read-only memory files) available through piracy or archival sites.
The era of the 3DS is over. But thanks to ROMs, emulation, and passionate archivists, its games will never be forgotten. all 3ds roms
Conclusion
Where to find 3DS ROMs