Nano Assault EX will be available on the 3DS eShop in Europe and Australia on March 7, Shin'en Games announced on Twitter last week.
According to the game's official site, Nano Assault EX is based on the original retail version of Nano Assault, and includes Circle Pad Pro support, online rankings and a new survivor mode. The game has been approved for the US eShop and is awaiting final approval for Japan; no official release date has been announced for either region.