Double Dragon 3: The Rosetta Stone, the third and final chapter of the popular series Double Dragon, is a side-scrolling beat 'em up created by Technos Japan originally as an arcade.
Unlike Double Dragon and Double Dragon II: The Revenge, which have been developed directly by Technos, The Rosetta Stone was commissioned to an external developer, East Technology. This is why the game has a completely different look and feel compared to the first games.
The arcade version was released in 1990, while the Amiga, Atari ST, ZX Spectrum, and Commodore 64 versions were published in 1991. The DOS version was released in 1992.
From GamesNostalgia you can download the Amiga version.