TedEH
Cromulent
I'd put something like the 3ds remakes of the Zelda games in that grey area. At first glance it looks like everything was just made to look a bit nicer (It's a remaster!) but if you dig a little farther you realize that parts of it have been either heavily tweaked or potentially re-implemented entirely (Maybe a remake...?). Same with the Diddy Kong Racing remake. It's 80% the same, but a bunch of new things were added, some mechanics altered, etc..
There are lots of things in between "some visuals were updated" and "we started from scratch".
There are lots of things in between "some visuals were updated" and "we started from scratch".