Just looked at the screenshots I took, and I assume the reward for playing "creatively" is the "Raw Memora" points at the end. As I said, a terrible idea, because it will make me think about the game on a meta level (= unimmersive), and maybe even force me to do unnecessary things, as for the engine to reward me "creativity points". If anything like that exists, it should be in the form of an end-of-game appraisal/feedback, as in e.g. Dishonored 2 or the recent Prey, which both imho did a fantastic job in this regard.
Please note that if some mechanism like that existed in the original Underworld games, I was not aware of it, so it did not matter, and in any case I was never presented with a "creativity score" at any point. I just played in the game world, which to me had a level of simulation unseen at this point in computer games (and for a long time afterwards, maybe even today). I would call on the devs to honor at least this core part of what UW was about...
Giving players a multitude if choices is one thing (even if it carries its own set of problems), but forcing players along a certain line of play by directly rewarding a certain play style the devs prefer is something completely different, especially if other game aspects suffer along the line - and also runs counter to the promise "the choice is yours"...