I think the biggest turn off of the first Witcher is the unusual combat system, players are not familiar with it so they're stopped playing. But when you get past the learning point, it's a damn great game.
constantly swapping to different styles, tossing in spells between combos, all while dodging and twirling my way to get into a better position.
The combat was complex enough to enjoy while not being so complex that all you do is stare at cooldowns and not get to enjoy the absolutely awesome swordplay by geralt. His sword moves were amazing.