So I was pointed to playonmac by a friend who thought it might help me to play some things I've really wanted to play on my desktop system, which is my most powerful and favorite to use. Since I saw a screenshot of Star Wars: The Old Republic right there on your main page, I thought oh! This must work pretty well, even if it's not perfect.
I tried three separate times just to get the thing to install. It didn't even do that, much less run afterwards. And no, I don't have Catalina or Mojave, I'm running High Sierra.
I didn't send a bug report because I thought, and still think, that it's astoundingly stupid to require a login to your site, just to send a bug report.
A bit of advice: please don't put screenshots of something working on your front page, if it is not in fact working at all. I only registered to post this request, and to warn any other people away from making the same assumptions that I did.