The advantages of a generic engine are somewhat diminished when you have to make sure your game fits on a cartridge potentially as small as 256kB. You can't rea

The advantages of a generic engine are somewhat diminished when you have to make sure your game fits on a cartridge potentially as small as 256kB. You can't really afford too much overhead given to generic functions and structures that you don't actually need for this specific game. That early on in the industry's life it would likely not have been worth the investment in creating such an engine given the minimal return you get back from it.