Manami Matsumae, one of the composers for Shovel Knight, was also the composer of the game(s) Mega Man, Dynasty Wars, Final Fight, Mighty No. 9, and many others.
The inspiration for the well-accliamed mechanics of Shovel Knight were notably drawn from the games/franchises Mega Man, Super Mario Bros., Castlevania, The Legend of Zelda, DuckTales, and Dark Souls.
All of the music in Shovel Knight fits the complexity that would be within NES CPU limitations, and even is capable of being played with full accuracy on a NES.