An N-Art is a map that relies solely on visuals over playability, showing off what one can do with Ned artistically. They can be incredibly challenging to create, as Ned was not created with purpose to build this style of map. Amazingly, some people manage to overcome this obstacle and create some fantastic works of art.
A short while into the recent history of N-Art implementation, many users began to dislike the category, as its offspring were flooding the Top Rated page of NUMA. Most playable maps were rated lower than these maps, and thus arguably did not get the attention they deserved. This situation led to Arachnid's implementation of Playable and Non-Playable sections for NUMA, allowing those who did not believe N-Art to be the same level of craftsmanship as Playable maps to have their own Top Rated list.
NOTE: N-Art does not count towards a user's Playable Rating.