The C64 was very similar in performance capabilities to the NES, and they share some chipset lineage.

It really was a time of a step change for multimedia software.

The C64 was the first modern, affordable, multipurpose consumer computer with decent sound and graphics (and tons of software, including desktop publishing, business stuff, etc.)-- the NES was the first console doing the same, with of course more of a focus on games. Many of which people still play today.