I loved this game back in 2007, before a lot of patches made it better, I love it today, when some of its parts are very outdated. It’s still an amazing adventure in a truly unique world with great story, witty dialogue and Slavic mythology. Though, if you play it in English, it will lose some of its charm (note, I recommend playing it with Polish voice acting even if you leave text in a language you do understand).
Even without some amazing mods (Full Combat Rebalance is almost a must for more fun play), which can make the rather annoying fighting much more fun, this game still holds up. The animation might be stiff, some events look visually silly, but there’s enough amazing stuff happening for your imagination to fill the blanks and see what the game wanted to show, instead of what it actually shown at times.
The main draw of the game is a story, so if you find gameplay lacking, fighting frustrating due to silly bugs that plagued Aurora engine (and a lot of BioWare games based on it), just don’t feel bad, switch to easier mode, install the FCR mod (the fights will actually end faster with it) and enjoy the witchering adventure at it’s best.
And no, you don’t need to know the lore or read the books before starting the game, in fact, some of it is more interesting to experience before reading the books, as books will undoubtedly colour your choices in the game.