NESmaker is a software tool for creating brand new, hardware playable, cartridge based games for the Nintendo Entertainment System...without having to write a single line of code.

A few years ago, while developing our NES game engine in the archaic 6502 Assembly language, our team (made up of mostly non-programmers) realized that we needed a much more efficient method for rapid prototyping and testing.  Instead of digging into the assembly every time we needed to make changes, we conceptualized wysiwyg tools for common tasks that would output, reorganize, and manipulate the underlying code; developing screens, building animations, altering AI...things like that.  We recruited Josh Fallon, tool developer extraordinaire, to help realize these tools.

Before we knew it, we had inadvertently created NESmaker.

More here https://www.kickstarter.com/projects/1316851183/nesmaker-make-nes-games-no-coding-required#