Some Backers have already received their rewards, and we're still sending the rest of them out. Please keep in mind that we have to manually e-mail everyone, including checking ringtone choice and then copy&pasting Steam codes.
Everyone will have their keys in their e-mail before the game can be downloaded on Steam tomorrow. If in doubt, though, please make sure to check your spam box of both the e-mail attached to your Kickstarter account and the one you entered into your e-mail preference box on the survey (if they're different).