For those looking for a fun, simple DIY project, maybe you'd like to build your own Famicom cartridge.
 
This set includes all of the components needed to build a working Famicom game, and it also includes a brand new Famicom shell, in which the PCB can be housed. Detailed instructions show you how to assemble your Famicom game in this fun DIY project.
 
Included on the ROM chip is a small demo.