http://www.fileplanet.com/21694/20000/fileinfo/Septerra-Core-Demo
It's hosted at File Planet, so you'll need a username/password. I couldn't find it on a nonprotected site I trust. If someone finds one, feel free to post it.

That's what bugmenot is for.

never heard of it, but I wouldn't use it anyway. I've had a fileplanet account for years.

I hardly ever use fileplanet, so I don't find registering for it to be worthwhile. It's just as easy to grab a login from bugmenot.
For added convenience, there's also a Firefox extension.

I have a tendency not to trust sites like that. So...I wouldn't ever use it.

Two questions on the demo, if you know:
- Does it work on Vista?
- Is it DRM free?
If both of those are true, I might grab it....

Yes (running 32bit here).
It appears to be DRM free. It doesn't install anything, it's just a zip file with the program's files in it. Just unzip and play. No UAC prompts when run either, so it's not trying to sneak garbage into your system directory or registry.

Excellent. Thanks.

This was posted in the demos thread. :P