From a strict legal standpoint, downloading ROMs of games you do not physically own is considered copyright infringement in most jurisdictions. Nintendo holds aggressive intellectual property rights over its catalog and actively issues cease-and-desist orders to commercial ROM websites. The Library Exemption
Beyond retail games, the platform hosts preservation projects for fan-made English translations of Japanese-exclusive DS titles, allowing global audiences to experience unlocalized games. How to Navigate and Use the Archive for DS Games