This is really not about the engine. But to make the game practically IDENTICAL to DOS2??
It was not made to look like D:OS 2, and there are significant differences. During development, games don't start off looking like the final state. The first presentations of D:OS 2 looked like D:OS 1 in a lot of respects, as well. As the core components / systems get finished, and assets are created, they get added to the game. The save system wasn't added yet in the build used in the presentation, so why do you assume the lighting and camera systems, character models, et al, are finished?
