You don't roll under them. You just move around until he moves to a spot where one of his horizontal lasers turns off because he's standing there. Move to the next spot while he's reloading. Do that and you'll reach a point where you can't go anywhere else. You'll see a PC on the floor. Use your EEV (or whatever it's called) to remotely access it and disable the lasers. Pick up your weapons, kill Emile and Disable the Nuke. There's a 3 minute timer. I don't know what happens if it runs down to zero. I completed it about 1 hour ago.
Yeah, it's quite decent, but I doubt it's better than the real "next-gen" release of it. The graphics are really strange though. Sometimes the in-game graphics are better than the cut-scene's graphics but the cinematic cut-scene's graphics are absolutely marvelous. They're so realistic. Controls are great too, plus it's got a great replay value, because there are many choices you can make in-game that, basically, affect the storyline.