I'm really happy to see a pascal game engine tackling more middle-ware features, a lot of the 'game engines' here are actually graphics engines, sometimes with audio, window management etc often enough extras to be considered engine frameworks.

High level things like scene management, path finding, AI and customizable entity/creature classes are not often represented so you get a big thumbs up from me! any commercial game engine comes with such things and indeed, commercial rendering engines are defined by the lack of such components, being designed so companies can drop in a wide range of middle-ware or to integrate into their own engines.

There are more than a few game ports that have switched rendering engines in such a way, an example that sticks in my mind is the game 'Bully' (Canis Canem Edit) which switched it's entire rendering engine for the enhanced PC version in order to take advantage of more modern graphics features.

This example and others like it highlight the fundemental difference between graphics engines and game engines and I believe looking at your feature set you are accurate to call Castle Engine 4.0.0 a game engine.

Keep up the good work!