I launch Voxatron, select Chaos Fortress, Run, the title screen appears. If I touch 'control' or 'command', voxatron crashes. I reproduced the crash with Hug Arena. Happy to provide the crash report if needed.

The cart selection screen doesn't have this problem.

macOS 10.15.7
Voxatron 0.3.5b

Voxatron became less stable on Mac OS as OS got upgraded in recent years. It crashes in Designer as well when you try to re-span by pressing X or overweighting files with Ctl+S
Short of new version of Voxatron I don't think that can be helped.

@zep - I'm a software dev doing macOS apps as a hobby; I'd be happy to help out.