I'm not really eager to have this application install firejail system-wide on linux. It'd be much better if it detected that it was already installed. Replacing system-installed packages is dangerous, and a serious security risk (what if this version of the application is outdated with a security problem that the system install doesn't have?)
Alternatively, using the firejail utility locally may also work, instead of mandating that I replace the system-wide version with some random version off the internet.
EDIT: yes, it turns out this error only happens through the app. App launches just fine downloaded from the web, or if I launch it from the downloaded folder. I, however, have never encountered this error on itch before. This is almost certainly a configuration problem with this package.
Now that I've played it, it's quite fun! Got me a bit hooked (I must admit that I'm a sucker for Cellular Automata).