[CoryAlexMartin]

There actually were things of note from the early demos that didn't make it into the final game. For example, the way you created your creature had gameplay implications. Things like limb length, limb count, limb placement, center of mass, etc were going to influence the viability and pros and cons of your creature. However, there were philosophical disagreements between team members and ultimately the decision was made that they'd throw the systemic approach out the window in the name of cosmetic freedom.

Personally, that isn't the decision I would have made, because I think the game is more shallow because of it. Maybe it would have made the game less enjoyable for people who just want to make whatever they want with no consequences, but that could have been solved with a difficulty option.

[Levitz]

Entire sections of the game were cut. I remember a puzzle section at the very start in which you had to combine aminoacids to start creating life that never made it, for example.

The option to be a water-based species didn't make it either.

The game did overpromise and underdeliver, hard.

[kevinmchugh]

I've seen it hinted that the ~half dozen designers had pretty different visions and that seems to have caused a bunch of churn and disagreements.