It depends on the VN and its implementation. The existence of things like Slay the Princess, 999, Raging Loop, Phoenix Wright, AI: The Somnium Files, these are all inextricably linked with player participation and choice, as well as very dense narrative.
Then you have ones like Steins;Gate that don’t have very much choice at all, that’s a lot closer to a book in most respects, but as a blanket VNs are, more often than not, absolutely games.
It depends on the VN and its implementation. The existence of things like Slay the Princess, 999, Raging Loop, Phoenix Wright, AI: The Somnium Files, these are all inextricably linked with player participation and choice, as well as very dense narrative.
Then you have ones like Steins;Gate that don’t have very much choice at all, that’s a lot closer to a book in most respects, but as a blanket VNs are, more often than not, absolutely games.