Instructions
Go to the "Cube Spring" game website. A link to the site can be found in the References section.
Select the "Connect with Facebook" link on the right side of the screen. Doing so will open a Facebook login screen. Log into your Facebook account using your email address and password.
Select the "Allow" option at the bottom of the next screen. This will allow the Kongregate website, along with the "Cube Spring" game, to connect to your Facebook profile.