Re: 32 bits won't run but has before?

@kbeardsley76  It sounds like you may have updated your operating system to one that doesn't support 32-bit apps.  Mojave was the last one that did; Catalina, released in fall 2018, does not.

There is no 64-bit version of Spore.  If you want to play it, you'll need to reinstall an OS that can run it.  Reinstalling Mojave or earlier on your internal drive would mean wiping your data.  Apple generally blocks the installation of an older OS than the current one on an external drive too, but there are ways around that if you know what you're doing.  You could also use a different Mac, one that hasn't been updated yet, to install Mojave on an external, then plug it into your current computer and boot into that when you want to play Spore.