Doesn't work at all with 2-finger scrolling on Safari for Mac.

Or Chrome. I had no idea it could scroll at all and closed the tab before seeing these comments.

Update: even weirder, it does scroll somewhat, but gets stuck and won't respond to two-finger scrolling. All in all a terrible idea for navigation.

Why not just use the links on the left?

Misses some animation but still gives you all the info.

For starters, the links on the left never show that there are two screens (even with scrolling that is harder to see than in should be). Why not just make a site that works?

Even if it was perfectly calibrated, it's still wrong thing to do. Scrolling is for scrolling. As in, position. On the page. People shouldn't use it for flipping between slides or animation states for the same reasons they shouldn't use links for buttons, buttons for links, or implement fake radio buttons using checkboxes.

This would be less of a problem if browsers/HTML had something built-in to manage pagination and page states. But hey, we got WebGL and sound APIs instead. Clearly, pagination (which is implemented in pretty much every single website on the web) is less important than rendering 3d objects.

Why not just click the mouse wheel and drag the mouse down?

Laptop users don't have a mouse wheel. Others may not have a mouse wheel on their mouse.