This distinction was important at the time.

> The jump from single-screen or flip-screen graphics to scrolling graphics during the golden age of arcade games was a pivotal leap in game design, comparable to the move to 3D graphics during the fifth generation.

> Smooth scrolling on IBM PCs in software was a challenge for developers.

Source: https://en.m.wikipedia.org/wiki/Side-scrolling_video_game

Very true, I think of it as a side-view platformer but of course it wasn't a scroller.