BeamNG.drive Alpha Access
Your purchase of BeamNG.drive Alpha Access grants you a serial key with which you can download the game and update it to the latest version.
Online authentication is only necessary to update; the game itself does not need an internet connection to run.
You are guaranteed free updates to BeamNG.drive for all future versions.
You also get access to a section of the forum where you can talk directly to the devs and report bugs, suggest features, etc.
The forum section also contains 3rd-party content, including vehicles and terrains.