The ME262 was a jet, not a rocket, and the allies found that even thoug it was much faster than anything they had, it was not as manuverable, so they out manuvered it to make the kills. The German flying wing used the same engines as the ME262, which were unreliable, causing the crash of the first prototype, and the second prototype was not finished before the end of the war. They were also developing a larger bomber version that was to use 6 engines, and would have had enough range to hit targets on the east coast of the US. If the Germans could have held on another year, the out come of the war might have been much different. It's a good thing that Hitlers ego caused him to make so many bad decisions.