For me it’s how narrative driven the game is and how the devs wanted to create something unique. It could have been another bland Ubisoft type of open world game with a nice open world but terrible writing, casual gameplay so even 10 year olds keep up easily, quantity over quality side content etc.
Instead we get a very well done human protagonist who isn’t another power fantasy. The combat is actually not easy from the beginning and takes time to get adjusted to, it makes it more immersive to learn stuff from the beginning yourself.
The story while incomplete is also well told. I like the Czech setting and history, very rare for someone in gaming (or otherwise) to focus on that instead of another Medieval England rip off