On Aug 2019 I wrote to Simon:

"2) The next version of Mac OS (Catalina) will be completely dropping support for 32bit applications such as the Mac OS release of Cultris 2. I sincerely hope its possible to release a 64bit version so that I and the few dozen other Mac players can update freely. Would love to know from you if this will be possible or not."

His response:

"I know about the issues with OS X in general and the C2 OS X version specifically. Unfortunately, I don’t run OS X myself and don’t have an Apple developer account. For these reasons, a new OS X version is currently unfortunately somewhat unlikely."

I hope this changes (apple developer program is cheap and has many fee waiver options) but am doubtful. There has not been an update to c2 in many years. 
 

I have the same situation, this may help you: http://gewaltig.net/Forums/Thread.aspx?pageid=1&t=1075~1#post8400

for Catalina, we have solutions ...

http://gewaltig.net/Forums/Thread.aspx?pageid=1&t=1045~1

but now, the Big Sur T_T