I cannot for the life of me use the .sit files for this game on the site.

In the end I had to use a .zip file from archive.org (version 1.0) which even then was very difficult indeed to extract on my SE/30. I needed to extract the zip on a modern system (maczip would corrupt the files) and then amend the creator and type codes of the image files to match a Dc42 image type - which I was only able to deduce by finding a real floppy disk to create a new image with and then inspecting it with FileBuddy.

Can the files be re-uploaded in a sensible format (.sit.hqx presumably)?

What is "the site"?

I just now did a keyword search in our Resources section for "Earth" and "Simearth" but I didn't find any results, so I assume you're referring to some other site?

The site = The Macintosh Garden. This post in in that subforum, perhaps you browsed it from a list of all recent posts.

It's a Stuffit 5.5 archive, unstuffs fine with 5.5 - will not work with older Stuffit versions. One could reasonably argue a 1990 game should not be stuffed with 5.5. You can use https://restuff.jcs.org/ to re-stuff it :)

That's odd. I'm using an SE/30 running 7.0.1 and I have Stuffit Expander 5.5. It seems to corrupt every time. I'll try that Restuff tool - very useful thanks.

Got it - Stuffit 5.5 Engine can't run on 7.0.1 so even when using Stuffit Expander 5.5 it can't unstuff v5.5 files. Worked fine on System 7.5.5. Probably should be repackaged given that it's a game that runs on old B&W Macs.