While it sports the same cover art and title as the NES game, Game Boy's Battletoads is a whole different game. The original Battletoads was later ported to Nintendo's handheld as Battletoads in Ragnarok's World.
Later after that another Gameboy game that was a copy of the NES version was released as Battletoads in Ragnarok's World, with a small change making it only 1 player. Between 1 and 2 years later Battletoads & Double Dragons was released ...
It was first on the SNES in 1991, and was later ported to the Amiga in 1992, the Sega genesis and game gear in 1993, , the GBA in 1993, renamed Battle toads in Ragnarok's World, and finally the Amiga CD32 in 1994. ...