The letter was the floor prize on floor two. It's sitting in the chest next to the ganon statue above the warp that unlocks the shortcut. Every floor has a prize item at the end in the shortcut room. By now you should have a spin attack, the letter, the blue ring, the flippers, and, at the end of this floor, a better glove.
The key you're missing is in the chest you're trying to reach.
I didn't get the letter in the level 2 chest…. I got a bottle instead.
Im also not finding the area outside that Ive got to blow up…. Any pics?
I got the 4 keys in level 4 but can't figure out how to get to the lock blocks.
Check the lower sections crossroads again… go in the III section, and go left, then down. There's a block hidden behind a tree you can hookshot to.
Edited by Joki, 25 October 2014 - 01:34 AM.