Here's a video of Donkey Kong Jr. from level 4 thru the end of level 6. The game doesn't get any more difficult after level 4 so this is really all you need to get to the kill screen... oh yeah... you also need to be able to concentrate for a couple hours on just DKjr. 
http://www.youtube.com/watch?v=mxgYFWe4F-Q
http://www.youtube.com/watch?v=mxgYFWe4F-Q


