Mega Cat Studios Design Blog
Mega Cat Studios is responsible for tons of modern NES releases like Project Blue, The Meating, and Little Medusa. They also have an awesome blog where they share design and development lessons from the process of creating their games. I find it a bit hard to navigate, though. (So many tags... I assume it's an SEO thing.) Anyway, here's an organized listing of all the NES-relevant posts I could find. I also included their handful of Super Nintendo posts, because I love the SNES.