youre telling me a "game engine" is this thing that updates a bunch of subsystems in a tight loop for I/O, graphics, sound etc, provides a way of loading/streaming data from disk with caching and background streaming, manages the execution state of units of code which run on specific conditions and themselves may trigger other code, offers features like a GUI framework and multimedia codecs, and provides a platform layer so that all this can run on a variety of hardware? mate. thats called an OS