Serious Sam Classics: Revolution is a unified version of the Croteam's original Serious Sam Classic: The First Encounter and Serious Sam Classic: The Second Encounter experience, which is currently in development by Alligator Pit, an indie development team made of Serious Sam fans with the support of Croteam. Serious Sam Classics: Revolution, along with newly developed content by Alligator Pit, also includes all levels from both Classics and is powered by an updated Serious Engine 1 featuring all-new advanced graphics shader support, full 64-bit compatibility, full Steamworks integration, and lots of bug fixes for a superior game experience. Serious Sam Classics: Revolution is a standalone product and it is completely free to those Steam users that already own both original Serious Sam Classic games on Steam (Serious Sam Classic: The First Encounter and Serious Sam Classic: The Second Encounter).