since this is a compo for making games with nesmaker, i dont think it's necessary to write "joe granato" to every game really, though ofcourse what you said is true, we're all sitting on an engine he wrote.
as for other people, the way i planned on doing my credits was just to thank the nesmaker community, and list myself and a friend of mine who works on some engine things as programmers, and the composer (you lol) as a composer.
i dont know about others, but whatever i shared on the forum i handed out there for anyone to grab and use and modify as they wish and while im not complaining if someone feels i helped them enough to get mentioned there, im not expecting
or requiring that. being credited from public domain scripts is more like an act of courtesy than a requirement really, unless someone explicitly stated that the use of their scripts requires creditation, which i dont recall seeing for anything anyone shared so far. (granted i've hardly gone through every forum post of every shared script here, so i might be wrong.)
obvious exceptions would propably be things like jorotroids scroll core, which is so massive that i feel if i would implement it on the compo demo, it would definitely warrant a creditation.