Before you complain go here: https://www.humblebundle.com/resender
Type in your email and submit the form, an email with your key link (and all the other Humble Bundle keys you've bought) will be sent to you. If you still do not receive your key then get hold of someone at Stainless or Humble to figure out the problem.
If you backed less than $25 on Kickstarter or less than $35 on Paypal you will NOT be receiving a key until the 27th.
Can someone sticky this thread? :)