Back when Nvidia was hosting their Black Friday / Cyber Monday sales, one of the features for this sale was the Green Box Bundle which featured games from Valve such as Portal and Half-Life 2. One of those games was Half-Life 2: Episode One and was only available in that bundle for people who purchased an Nvidia Shield tablet. Now the game is officially available for anyone who owns an Nvidia Shield tablet.
Half-Life 2: Episode One is the sequel to Half-Life 2 which builds on the single-player campaigns within the original title. As the story goes, players will be "Stepping backing into the hazard suit of Dr. Gordon Freeman and face the immediate repercussions of your actions in City 17 and the Citadel. Rejoin Alyx Vance and her robot, Dog, to once again aid the human resistance in their desperate battle against the totalitarian alien menace of the Combine."
For those of you who want to pick up Half-Life 2: Episode One for your Nvidia Shield tablet, you can do so through Tegra Zone or Google Play for $7.99 which is the same price this game sells for on Steam. This is an Nvidia Shield tablet exclusive game for right now.