The Nanostray virus fought in the games by the same name on Nintendo DS isn't totally dead it seems, and it has to be fought again to save the Nano Cosmos from destruction. That's as much story as there is to this game. It makes no mention of it whatsoever and even the bundled digital user's manual makes no reference to any story. The Nintendo eShop summary is the only source of information directly available on the console as far as story goes.
Never mind that, because whereas some might have this silly idea that RPGs don't need a story (yeah, no kidding), shmups truly don't need a deep one to be great. That's not to say that an interesting backdrop isn't a welcome thing either, but dismissing a shmup for its lack of plot would be a grave mistake.
Imagine now a game world similar to Super Mario Galaxy, in that the little ship, instead of being pulled forward by an automatic scrolling like in most other games of the genre, has the freedom to move around what looks like a little planet, in every possible direction. That's pretty much the basis of the gameplay in Nano Assault Neo, right there. In each level, the nanite ship moves around a living cell that is being infected by viruses, bacteria and other parasitic microscopic creatures. Moving the ship is done by moving the left analogue stick on the Wii U GamePad, while shooting, interestingly enough, is handled with the right analogue stick. This is identical to Geometry Wars and the much older arcade classic Robotron: 2084, which initiated the genre in the early 1980s. Here, however, bullets follow the shape of the tri-dimensional cell around which the ship is travelling.
Being able to move in all directions while shooting in any direction at the same time takes some getting used to at first, especially since camera angles aren't always helping gamers in keeping their sense of direction. Past an initial short period of acclimatisation though, they should feel right at home.
Enemies come in various species types, with their own behaviour and attacks from all directions, instilling a constant sense of thrill and panic in the player as the difficulty rises with the different sets of cells. Each cell must be disinfected before moving to the next. To do so, the player has to exterminate 90% of the enemies living on it, which in turn primes the cell's automatic sanitisation process and opens the exit to the next cell. A countdown then starts, and 30 seconds remain to reach the exit. During these remaining seconds, one can either reach the exit and leave the remaining enemies to be destroyed automatically, which yields no bonus, or aim for the 100% purification of the cell which is rewarded with a beefy bonus. Failing to reach the exit before the countdown ends destroys the entire cell but opens the path to the next one, just with absolutely no reward.
Cells are grouped in sets of four, the fourth one always housing the boss of the difficulty level selected. There are four of these sets of cells, each with an increasing level of difficulty named after letter of the Greek alphabet, which amounts for a total of twelve standard levels and four bosses, each lasting a mere few minutes. Between each cell, players get to spend credits they picked up during the previous stage on extra weaponry, bonuses and more lives, to further help them in facing the ordeals to come. Additionally, beating smaller enemies with a certain requirement within each stage makes letters appear, that spell the word "BONUS."
Collecting all five letters opens access to a bonus stage that plays much like the tube tracks in an F-Zero game, where the player fast-forwards inside of it and has to avoid crashing into obstacles while collecting as many credits as possible, to be spent in the aforementioned Nano Shop. Crashing once ends the bonus stage instantly. The longer one survives in it, the more extra points this adds to the overall score for that set of cells.
There's no real ending sequence after clearing each of these sets, which is in line with the total lack of any introductory plot, and a huge disappointment altogether, since it removes some of the sense of accomplishment that comes from actually beating the game...
Unless, of course, there actually is an ending awaiting at the end of the Survival mode, which pits players against all the levels in the game in chain, with their order randomised and with one single life and no way to gain any additional ones. However, that challenge proved a bit too hard to beat for your servitor, so that can't be presently checked. That mode has to be unlocked. Arcade mode, on the other hand, lets you choose from any cell completed in solo, to try and get the best score possible on it.
Shin'en was kind enough to allow for a two-players co-operative mode. Player 1 plays on the GamePad, while Player 2 plays on the big screen, using either the Wii U Pro Controller, a Wii Classic Controller (Pro), or the traditional Nunchuk and Wii Remote combination. The first two play just fine, given that they come equipped with two analogue sticks and allow for the exact same input scheme as the GamePad itself. However, the Wii Remote and Nunchuk combination requires aiming with the D-Pad, which obviously won't allow for the same degree of precision in directing shots. Also, it should be noted that the single player game can only be played with the GamePad.
In co-operative mode, both players play the exact same way as in the regular single player mode. They don't share their weaponry and credits count. However, if one player runs out of lives first, they can steal one from the other, if the latter has any remaining. Bonus rounds are also available in co-op. Strangely enough, a mini map is there to help players keep track of each other's position around the cell, as well as enemy units and even the exit once it opens. It would have been handy to have it available in single player mode as well, since it proves extremely useful. Lastly, Player 2 on the big screen can see Player 1's nanite ship being labelled with a tiny bubble in which Player 1's face is displayed, filmed through the camera of the GamePad. It's gimmicky, serves no purpose, and can be deactivated in the options, but is a fun inclusion nonetheless. Seeing as that has been implemented, it can only be wondered why online co-op wasn't included. It would have worked extremely well, coupled with voice chat since co-operation in that mode really encourages players into making verbal exchanges.
The game ultimately feels extremely short. It offers a decent challenge for moderately skilled players, but still shouldn't last more than two or three hours at most, unfortunately. However, online leader-boards are there as an incentive for players to come back and improve on their previous performances, and the co-operative mode is extremely fun. Finally, as anyone can witness, the game looks gorgeous. It offers the possibility to be played in single player without the TV. However, the best experience remains the one on the big screen, since then you get the full 1080p experience, and the larger display allows for an optimal visibility of enemies and their shots.