A Nyan Mario Mashup is a mashup is that has the quality of Nyan Mario. With Nyan Mario Mashups, the bpm generally isn't matched and the mashup sounds like absolute garbage. A really popular example is The World Is Number One. The video as of June 8th, 2017, has 1,056 views, 42 likes, and 41 dislikes. I mean, LOOK AT THAT LIKE TO DISLIKE RATIO. Doesn't that show the amazingness of Nyan Mario mashups? Nyan Mario mashups traditionally get less views than his other types of videos because people clearly know that the mashup is going to be trash.
Nyan Mario acknowledges that his mashups are bad. If somebody comments "this mashup is good", Nyan Mario will reply something along the lines of "wait... this is good???" and it is generally like this for most of Nyan Mario mashups.
Nyan Mario mashups don't really recieve a good reception. Memers generally rate them 2/10.