I'd have to critique the creature builder as well, for some entirely unnecessary limitations. You can't use the carnivore or herbivore mouths if you're an omnivore, or vice versa etc. So if you want to have an herbivore with mandibles, you can't, because mandible mouths are only for carnivores. That limits both aesthetic and gameplay possibilities for no particular reason. You can just use the external creature creator and mix-and-match all you like, and then inject that into the creature phase, but then you miss out on being able to upgrade and evolve your creature over time.
After creature phase the polish on the game really starts to go down hill, but what really grinds my gears is how weirdly generic the vehicles are. Ground vehicles launch a single arcing projectile, Sea vehicles fire a single arcing missile, Air vehicles fire a tracking downward beam. This too kind of infringes on creativity.
That to me is the most damning issues with Spore, it's a game where, if nothing else, you can be creative.. and then there's these funky little limitations that infringe on that creativity. It's not a total failure in my eyes, it's still a pretty cool toy and I've spent probably a total of 2 weeks with it since I picked it up on release day, but it's notnearly the game that it could've been due to dozens of little balance issues.
The game can be a challenge, I'm a vet at spore by now but when I set it to Hard I died horribly the first time I played Tribe, and couldn't get through Civ phase at all.. at least not as an economic civ, which isn't able to directly attack enemies.
I use a 'Space is Fun' mod that reduces the occurence of attacks and epidemics so you're not constantly getting interrupted. It /is/ a lot funner this way, but there's a massive amount of grind in getting some of the badges. I tried for days to get the Holo-Projector tool -- it lets you beam down to planets and interact with (well probably just -look at-) creatures and tribes and such up close. I gave up after 4 days. I had to just jet around burning up time and buy up 50 systems or so to get the Trader 5 badge or something. Meh!
If they'd had the degree of complexity and interactivity shown in the GDC 05 video, perhaps the massive galaxies and far-off goals would make sense. But as it is, it's just too much of the same and I end up getting sick of the same old crap. Aside from a few super-weapons that some civs get, every race plays the same in space so there's really no replayability or variety to be had.