Surprisingly enough many video games have been influenced heavily by the Middle Ages. While ideals from those times lasted for several decades, and sometimes centuries, it's odd that some are kept around for our entertainment. There are, of course, games that are based during that times period, such as Assassins Creed. Yet there are plenty of other ones that just have ideas, and theories from that time. For example, Bloodborne uses the Miasma theory that how something smells decides whether it is a malevolent thing or not. This goes for monsters and diseases. The game even included the myth that incense would keep monsters and diseases away along with having a plague doctor mask item in-game.
Besides this there are many themes and settings that are reminiscent of the Middle Ages. The majority being that the main world/political power at the time is the Church. Other times it is just a reference to historical fiction, or historical figures. The use of Dracula is extremely common especially with Castlevania.
The only unsurprising thing is the common use of mythological monsters from the Middle Ages along with the amount of Middle Ages styled weaponry such as swords and bows. However, the use of them can be surprising with the developers occasionally giving the items a backstory and specific name. While this is often cliché ones such as Excalibur, and only for rare in-game items there is an occasional game where every item has a backstory and specific name. This also goes for the creatures and enemies in a game as well as other items that are not weapons.