That is a well-known reproduction cart. The only known version of Earthbound for NES was a review copy prototype that was never put into production. It's often referred to as Earthbound Zero.
An English localization began immediately, with firm plans for a September 1991 release. An 80-page instruction manual/player's guide was produced. The game's odd soundtrack, orchestrated and performed by Suzuki and a band of unknown British singers, was prepped for release. Things… worked out a little differently.
http://starmen.net/mother1/