Amusement Park Project zip file invalid?

On the webpage: Getting Started with RTX Showcase | NVIDIA Developer

The link for the Amusement Park Demo source zip file downloads a 63MB file (which looks too small), and when I open it it says it is an invalid zip file. The download for the binary works and I can wander through the amusement park.

Are there any sample projects for NvRTX I can get my hands on? I am on the 5.6 branch, but would build an earlier version if I had to just to look at a demo project and learn from it. Thanks.