Horizontal scrolling just with the mouse

It can do something similar (i.e. scrolling with mousewheel and keyboard) via an extra js script (see example). Keep in mind that the plugin will not create the horizontal layout for your pages (i.e. it’s not a theme like the one you posted).

You can find more info here:
https://manos.malihu.gr/page-scroll-to-id-with-mousewheel-and-keyboard/