How to Claim Your Kickstarter Drifter Download
From Drifter
If you're a Kickstarter backer who's pledged $10 and above, you can claim your Humble Store download of the Drifter Beta by entering the email address you specified in your backer survey into the Humble Key Resender at the following address
https://www.humblebundle.com/store/keyresender
and you should get a link from Humble Bundle which will let you download the game and add it to your Humble Library.
If for whatever reason you still can't claim your download, shoot me an email at contact@celsiusgs.com and I'll sort it out!