Every horror movie claims for themselves that they kicked off something. Be it the slasher genre, be it the "let's go all in and not censor ourselves", be it the body count, gore, nudity, organs on display or whatever else you can imagine. In this case it is more the idea - although there are some short glimpses of visual and very explicit imagery.
Wes Craven and Sean Cunnigham (who worked together on this and then went ahead to make two of the most iconic horror/movie villains of all time respectively - Freddy Kruger and Jason Vorhees) may feel like they wanted more or rather be more diverse. Do movies in other genres - but I do think they can be happy with their career. And it started with a very controversial and evil little movie like this one.
The villains here are as despicable as they can get and the one moment where Wes claims they have a point of no return - well let's just say they are already past that way before that moment. So this is raw, it lacks sense in many respects and you can see there was not a big budget involved. But through it all you can feel the effect until today the movie had ... because of its success and because it was rough and did not really follow any rules