PC classics Half-Life 2 and Portal now available on the NVIDIA Shield
Half-Life 2 was originally released on November 16, 2004, following a five-year development. Same year, it won 39 Game Of The Year awards, and was crowned "Game Of The Decade" in 2012. It was followed by two episodic sequels, which aren't included in the Android version. Portal appeared in 2007 along with Half-Life 2: Episode Two. It has an unique gravity and physics-based gameplay that will get you "thinking with portals".