Re: Downloadable 2005 beta of Spore?

There's no such thing. The 2005 video was mostly a mockup (created by a visual effect system called Swarm), not a real game.

Taken from the personal website of a Spore dev who worked on it:

Swarm, the swiss-army-knife visual effects system I wrote that has featured in all the games I've worked on. In addition to general visual effect usage, it's proven a very useful prototyping tool, which has led to it being abused in various interesting ways well beyond its original design remit.

In particular it was responsible for 70% of the original GDC 2005 Spore demo. (Thereby unfortunately fooling a lot of people into thinking the game had already been developed.)

http://www.andrewwillmott.com/talks/swarm-procedural-content