The site positions itself as a library. Much like a physical library lends books, the Archive argues that providing access to obsolete software is a matter of historical preservation.
A common myth is that a work enters the public domain 75 years after creation. For NES games (1985-1995), that is false. Under current US copyright law (Copyright Term Extension Act of 1998), works created after 1978 are protected for the life of the author plus 70 years, or 95 years from publication for corporate works. No commercial NES game is in the public domain. The oldest NES games will not begin to enter the public domain until the 2080s. archive.org nes roms