Nano Assault

The bulk of the game is played in an overhead 360-degree shooter style similar to Geometry Wars where movement is performed with the analog nub and shooting takes place in all directions using the ABXY buttons. These stages take place with the microscopic ship of series fame flying over giant cells fighting off infections and viruses, and picking up DNA sequences. The primary focus of these stages is to eradicate all enemies and collect all DNA strands.

The second gameplay style comes in the form of 2.5-D boss battles which take place on a large circular area with a boss character in the center. Players move the ship left or right along a 2-D plane, firing into the background at the boss, or to either side against other attackers or pieces of the boss character. The primary focus is simply to destroy the boss character.

The third perspective is that of a 3rd-Person, behind-the-ship view flying through 3-D corridors within an organic body, firing on infections and other things. Players must dodge obstacles as well as destroying enemies, with dodging environmental hazards being important in this mode. The primary focus is survival culminating in a boss battle.

Besides the main Story Mode, there is an Arcade Mode wherein stages completed in Story Mode can be replayed for fun, high scores for Leaderboards, and to complete specific challenges set for each stage. Challenges include completing without dying, completing without using the secondary weapon, or obtaining a set high score. Completing challenges earns Nano Coins which are used to purchase songs for the Jukebox or enemy profiles for the Nanopedia.

Plot-wise, the focus of the game is similar to the previous entries, with players assuming the role of a nanite vehicle and traveling inside an organic body attempting to thwart the deadly Nanostray virus. The levels are broken up into Cell Clusters, with 32 Cell stages and 10 boss battles.