For the magic sword, you need the whistle. Go to the "northern overworld" (this where a totally new overworld map appears if you press the spacebar). Explore screens not too far from the entrance of this northern overworld, and you should find a screen with 3 green trees missing at the bottom (southern) edge. Use the whistle there and follow the path back to the southern overworld.
Perfect and thank you .
First left in the northern overworld, kill monsters, blow whistle. Follow path down and left, down stairs and right then bomb.
Not long after, I went back up the stairs, blew whistle again and the bushes went away.
I went left and up and found a room with three rows of bushes, the middle row double bushes. Blow whistle again and Level 6!
Thanks again,
Tom