Growing Rites of Itlimoc / Itlimoc, Cradle of the Sun
 
So, the big talking point with this card is the flipped version, and how it's literally the game text from Gaea's Cradle. That's quite understandable. The comes-into-play effect that comes with the enchantment side is a pretty standard one for green, and a useful one too, with the downside being that you only get it once. The fact that there's no repeatable benefit and you're looking to fulfill the transformation requirement with other cards prevents it from being an automatic inclusion in decks that can cast it, but there is still a very good payoff for decks that can afford to wait (slower, defensive formats like Commander come to mind).
 
Constructed: 3/5
Casual: 5/5
Limited: 3/5
Multiplayer: 4/5
EDH/Commander: 4/5

Growing Rites of Itlimoc//Itlimoc, Cradle of the Sun

The closest we’ll ever come to a Gaea’s Cradle reprint, Growing Rites of Itlimoc makes you jump through a hoop to get your Cradle, but it’s a manageable one all the same.

For three mana, you get to tutor out a creature card from the top four, so this slots in neatly into decks with lots of creatures (like, say, Elves). But if you can play this on turn 3 with enough tokens to make this work, you’re in excellent shape, since you get a Gaea's Cradle that still taps for green with an empty board. It goes without saying that it's quite powerful, and there are many decks this slots into (like Elves). The downside of flipping at your end step is not too bad, since it lets you leave mana up for some kind of answer.

I think Growing Rites of Itlimoc is going to be one of the star cards of the set. While I am unsure of how Standard will shape up, Legacy and Modern have a home for it (potentially), and the power on it is very real indeed.

Constructed: 4.25

Casual: 4.75

Limited: 4

Multiplayer: 3.75

Commander: 4.5