I've just got my copy in the mail yesterday (no Securom issues yet, and I can just crack the fucker when the install limit comes into play) and gotten through the cell stage. I was expecting something like fl0w, but it let me down. Of course, it's only a small aspect of the game, so I'll let it go.
Through the creature stage, I felt obligated to spend hours finding and chewing skeletons to upgrade my creature, and soon came to a point where I was unable to ally with other creatures, as they somehow have a trillion more DNA points than I do. Evolved my creature a second time, spending thirty minutes tweaking out (jeez, I'm still missing parts selection). Next thing I know, I can only ally with one race on the map (everyone else is notoriously difficult, even though I put points in as many possible social points as I could), chewable skeletons are scarce, and when I try to fly and land on big stumps or rocks, the creature doesn't set down. It just keeps flapping. The control's awkward and it's sometimes hard to turn, especially in the air.
When I updated my creature and spent awhile in pretty much the same land, I thought it autosaved. I thought I remember it telling me it did. I go to continue that game, and I'm back to square one, in the middle of the first stage creature area. All the work gone. Am I missing something? Do I really want to go back and redo it? The only thing that'd make it worth it is if I found out that I missed out on hundreds of DNA points (the unalliable creatures don't count; how the heck would you tame that area?).
Also, I've several creatures that I've built in the Editor demo (except none were as cute as the one I just built today), but I can't easily find where to activate them in-game.
Finally, I don't like feeling obligated to sacrifice a creature's style just because another similar object has better stat points. I can get used to it, but it took some effort to lose the pincer beak.