Another reason why we might want a new engine? More gimmick/gameplay options. The ability to cut power to a door, or, as a human, to fuse wires and power it, or as an alien, to spit juice (or something) to create an electrical connection. Lights that can be powered? Better shadows on players so that you can actually hide in the dark (give the helmet the ability to outline alien forms)? A flashlight would be needed, and the only reason we don't have one is because the engine won't like it, and it's not needed on the current engine.