Nintendocore fuses aggressive styles of modern rock with chiptune and video game music. Nintendocore emerged from metalcore, heavy metal, hardcore punk and post-hardcore, and has been influenced by a variety of other genres, including electro, noise rock, post-rock, and screamo.

The movement was initiated by the metalcore group Horse the Band, who originally coined the term "Nintendocore" as a joke. They have released five studio albums that demonstrate this style, starting with Secret Rhythm of the Universe, released in 2000.

Nintendocore frequently features the use of electric guitars, drum kits, and typical rock instrumentation alongside synthesizers, chiptunes, 8-bit sounds, and electronically produced beats.

Nintendocore groups vary stylistically. Some feature singing, and lyrics that mirror video game storylines. Others add screamed vocals into the mix: Horse the Band combines metalcore, heavy metal, thrash metal, and post-hardcore with post-rock passages; Math the Band includes electro and dance punk styles. Other groups, however, are strictly instrumental. While otherwise diverse, all Nintendocore groups use specific instruments to mimic the sounds of Nintendo games.

Along with Horse the Band, another Nintendocore pioneer is The Advantage, whom The New York Times praises as one of the groups who brought video game music into the mainstream modern music spotlight. The group plays nothing but music from the original Nintendo console games. By creating rock cover versions of video game sound tracks, they have "brought legitimacy to a style of music dubbed Nintendocore," according to the Harvard Crimson.

The rock group Minibosses are one of the most well-established bands in the Nintendocore genre, with an impressive roster of covers including Contra, Double Dragon, Excitebike, and other video game themes. Other acts include The NESkimos, The Depreciation Guild, Math the Band, The Megas, The Octopus Project, An Albatross, Rolo Tomassi, Crystal Castles, and Hella. Sky Eats Airplane has labeled itself under the genre, though Canadian magazine Exclaim! has disputed this labeling.