Complex sentence: The gameplay of "The Witcher 2" on the PC takes a marked departure from that of its predecessor, as movement is solely through the keyboard and combat moves from the rhythmic mini-game style of the original game to a more fast paced style.
Split into simpler sentences: The gameplay of "The Witcher 2" on the PC is a marked departure from that of its predecessor. Player movement is accomplished solely through the keyboard, and combat has changed from the rhythmic mini-game style of the original game to a more fast paced style.