Imagine if you can be in "dynamic mode" where you can add rules, facts, etc. in an adhoc way.
Then, once your game is better defined, you can compile the Prolog to native code so that it is highly optimized, executed in parallel, etc. The compiler could apply all sorts of optimizations we see in commercial game engines automatically.
This compiled object could then be embedded into a game engine with native performance.
Done right, this could even outperform imperative game engines, but be very easy to debug and modify.