Well, the difference is that one is a Visual Novel, and the other aren't. It's just a matter of game mechanism, and probably also a little matter of the uploader's taste (which isn't a criticism, it's sometimes difficult to make the difference between a VN and a none VN).
Is a game with a free roaming mechanism not a VN when there's always just on place to be at a given time ? Technically yes, but isn't it, in fact, just a VN with a none classical mechanism for moving from scene to scene ?
Is a game stopping to be a VN when the player can take decision that will change the story ? Technically yes, but isn't it just a none kinetic Visual Novel ? I mean, how many choice are needed for it to stop being a VN that use the modern technology to offer a little more variety ?
Is a game stopping to be a VN because there's grinding ? Or is it just a VN where the author copy/paste the same scene many time, in order to have a story as long as a book, in place of a short novella ?
And is a game with mini-game a VN that offer some distraction time to time, or is it effectively a none VN game ? I mean, is a book stopping to be a story because there's a crossword or sudoku between each chapter, or is it still a story, but with a little something more ?
The difference between a VN and a none VN is in the level of interaction. It's sometimes obvious, when it's a platform game by example, and it's sometimes way more difficult to tell if it should or not be classified as "Visual Novel". But in the end, what matter is the pleasure you take will playing it, not the genre of the game.
