Ah okay, will try that route. Wasn't able to download it from the website using the "traditional" method. Thanks for your post.
EDIT: Unfortunately that didn't work. I was able to download it and install it and login, but then the button just says "Purchase" and if I click on it it redirects me to the website. I guess kickstarter backers with only game-copies, just don't have access yet.
Well I'm a Kickstarter backer with only a copy of the game and not alpha or beta access (I paid £40) and I have access to the gamma, so perhaps you should contact support to get this sorted.