Oh, I don't doubt that, but I've already fulfilled my "space conquest" genre for now with SoaSE:Trinity. I just wanted to check out Spore because of the interesting-sound evolutionary aspect.
Spore is basically 5 mini-games in one - The only difference is that in Spore you sort of get to build your critter a little bit each time as you go.
The first game can be had for free in the game called Flow (which imho is much better).
The second is your typical "adventure" 3rd person over-the-shoulder type of hack'n'slash game. Think Neverwinter Nights, just not with quests.
The third is a small scale RTS game where you gather resources, build your home base, defend your tribe and kill or be killed.
The next is more city-building RTS on a somewhat more macro-scale (think Civilization) where you're now fighting for the entire world.
And finally, there's the galactic stage, which is more of the same.
My kids like it, it sparks a little creativity out of them. But honestly the stages are too short in my opinion. You can never make anything as intricate as the "premade" critters as you're playing the game - there are far too many constraints to keep your character from becoming too powerful too fast. In concept, it's a nice toy with a shell of a game wrapped around it.
GalCiv otoh is like Civilization in space - it's a completely different beast from Spore all together.