I don't have a good answer for you.

I can tell you that if your game requires substantial background processing, threading is likely to improve interactivity. I can tell you that Perl's threading models leave something to be desired. (Though by all accounts 5.6.x is better than 5.005.) Perl's threading is experimental and subject to change. And I would avoid Perl's threading for anything I considered important.

Beyond that you may want to read Threads vs Forking (Java vs Perl) for a good overview of the difference between threading and multiple processes, and some of the risks of threading. Some of which you might not encounter in Java because the language channels you towards guaranteed safe behaviour. All of which might be basic background to you.