Scroll down through the instructions with movement keys, then start with one of the action buttons. That worked for me
I’ve already tried using all the listed buttons while on the screen that lists them, but nothing is happening. that might just be something wrong with my system?

I tried the download, but for some reason it’s listed as 0KB and doesn’t unzip?
Through the itchio app, I was able to download the html5 version (which might be the web version), but even that isn’t responding to my keyboard.