It is not just the input. The demo app doesn't start up at all.
With chmod +x I can pass the "can’t be opened" notification. I also tried the spctl, but it won't start. The icon just bunch but the app doesn't come up. I had no problem before 10.15.
Oh, sorry, my guess is Apple decided to implement some new permissions/security stuff that wasn't there before. Or, perhaps it is trying to start the 32-bit version of Freerider (Freerider still includes both 32- and 64-bit executables for Mac). I tried searching for answer but I didn't find anything definitive, seems like a pretty common problems that some apps doesn't start after updating to Catalina though...
(Still, if the demo doesn't run the full version most likely won't either).