A sequel - whether it’s a movie, book or game - has two duties. On the one hand, it has to be faithful to the original; to have something of the old feel, a few old characters, and a few common threads to pull the two stories together. But at the same time, it has to take the series somewhere new - pull the characters and their story into new territories and new situations; embrace new ideas and bigger themes. The thing about iD and Raven’s Quake 4 is that it absolutely aces the first part. It couldn’t be any more like Quake II if it had been designed by the exact same people immediately afterwards. But then it goes and fumbles the second part. If Quake 4 didn’t look so damn cutting-edge, we’d have to label it a retro game and be done with it.