For everyone who's asking what time the game comes out:
The game is coming out on 8/28 for Xbox 360 and PC via Steam. We don't know the exact launch time, since Microsoft and Valve get to choose when they upload content to their stores (Microsoft owns XBLA, Valve owns Steam). This timing depends on a number of factors. For instance: at the time of this posting, it is 8/28 in some timezones, but it is not yet 8/28 everywhere.
However, you can bet that once it's available for you to download, we'll be posting about it here on Facebook.
The PS3 launch is still set for 9/24 in North America and 9/25 worldwide. We'll have more news on that as it approaches.
We're almost there. TURTLE POWER!