The links to the builds are up on the Steam page:
Steamcommunity.com
Please read the README file before playing the game, it contains important information about controls,etc (I don't have a tutorial yet).
You can leave feedback preferable on the dedicated thread on the Steam Greenlight Concepts page:
Steamcommunity.com
Alternatively, there is also the official Facebook page for the game, but try using the Steam page if you can :)
Facebook.com
