4A Games, developer of Metro 2033, admits they have built the 4A engine from ground up. But it looks like the X-Ray-Engine from STALKER and Sergey Grigorovich from GSC Gameworld states that he believes 4A Games have stolen their engine. Check the link for comparison shots.
A look back at 4A Games' admirably consistent post-apocalyptic shooter franchise.
Metro 2033 mechanics that would adapt perfectly to VR, and the upcoming Metro Awakening by Vertigo Games this year.
The Metro video game series started with a humble b-list title, before building a strong fanbase and becoming a pioneer in the industry.
