Nano Assault

Nano Assault is a shoot 'em up video game developed by Shin'en Multimedia for the Nintendo 3DS, originally published as a retail title by Majesco Entertainment in December 2011. It is the spiritual successor to the Nintendo DS games "Nanostray" and "Nanostray 2".
In March 2013, Shin'en published an enhanced version entitled Nano Assault EX, with visual improvements and additional gameplay features, and this version is distributed exclusively via the Nintendo eShop.
Gameplay.
Players blast their way through 32 twisted cell stages and dark worlds with rugged landscapes that adjust in difficulty based on the player's skill level.
Reception.
"Nano Assault" and its enhanced version "EX" have received mostly positive reviews, holding aggregated Metacritic scores of 75/100 (based on 8 reviews) and 74/100 (based on 16 reviews) respectively.