In my opinion, a rather biased one as it is, The Witcher series explores some very mature topics in its scope, though the games never managed to capture the tone quite as well as the books did. Yes, they are focused on the oldest cliche in game story history, that of amnesia, where Geralt wakes up without his memory or any recollection of the events that brought him to Caer Morhen, let alone the events that led to his assumed death years previously. The first game seemed only tangentially related to the books, with a few key characters appearing to guide Geralt through his path in the game. The player was then thrust almost without aid into a massive political intrigue, one guided by a figure closer to the throne than most would assume. It stuck reasonably close to its dark fantasy roots, without necessitating player knowledge of the books that had inspired it. Although some, myself included, would have probably enjoyed knowing a bit more about the events that took place between the books and the game, such an inclusion would likely have alienated those just picking up the series for the first time. For example, though Geralt is always referred to as Gwynnbleid, or White Wolf, or as his most common moniker, 'Geralt of Rivia', he is, in fact, not from Rivia at all, though he has been referred to as having a Rivian accent. Sex, and the pursuit of it, is a recognized part of both games, though the first made it more of an accomplishment with the cards the player would get for bedding certain women in each chapter. Admittedly immature in both tone and usually dialogue as well, these encounters always felt a little out of place to me. Despite these rather awkward situations, the game hinted at a depth of lore behind the world, one of the most notable examples being the racism and degradation aimed at nonhumans, both Elves and Dwarves. Here, for once, the story matched that of the books, as Geralt was in fact 'slain' in the Rivian Pogroms, along with his lover, Yennefer, who is never mentioned in the first game outright, and only comes into play in the second, as Geralt's memory begins to return. These details mark the maturity of the story of the witcher, though it's content may contain some rather less serious events.
Trust me if all of this [The Witcher] was real, being a Witcher wouldn't be much better than being a women in that world.
