Very, very impressive!
This game is, in short, brilliant. It's realistic in the way the different injuries/illnesses are treated, and gives a un-cutified version of how some medical practices were during the middle ages.
The only thing that I truly find missing about this game is a "continue from level.." button - it is a tad annoying that you have to go through the whole procedures again and again because you mess up one of the later ones.
There are only very, very few sounds, and that helps to enhance the feel of the game. The music is also very well chosen.
There is full interactivity, of course, due to the nature of the game, and also quite a lot of violence - though I would say that you get what you ask for when extracting arrows from legs, cutting open infected skin and decapitating vampires... The isn't much humour in this game - THANKFULLY! - but that would only have wrecked it.