Try to get yourself the second laser upgrade, and as many options as possible. Basically, shoot the purple crystal rocks until you can get through. Not much more that I could help you with. If you shoot enough you can cause a lot of slowdown, which is good since your ship isn't affected by it. Eventually, you'll get up to some big blue rectangular rocks, which just bounce up and down. When you get past them, you're almost at the end. Beat the (purple) Crystal Core and remember: Watch your back!.