I offer a solution to this issue. I hope it helps.
Current StarMade launcher, which crashed on pressing start game on Mac OSX 10.15 Catalina (New Macbook Air), was made to work by uninstalling all java elements, including jdk and jde as well as oracle and java folders, and then installing Java SE 7 for macOS 64 and the Java 7 jdk.
The game crashed only when loading the world for the first time (had to hard reboot) but second time worked wonders.
Hope this helps someone