Yeah, I made one but it was basically a bust. I have a thread on how to do it too, but I cut it short becuase of GG limitations.
If you want a game larger than 64KBs (yes, 64KBs) you are going to need to use one of the very few cartridges that have a designated mapper chip. Most of the cartridges, as well as the one I sadly used, have the mapping logic magically built into the ROM chip, which is incredibly uncommon for a company to do.
I will find you the list of worthy games in a second, if you don't use one of these, its useless.