Been playing this and enjoying it however I think I got stuck in the Garden Temple. I cannot find a key anywhere to progress. I originally thought maybe I missed a key in a previous dungeon (forgot bout the hidden knight key so couldn't finish the mountain temple for a bit, back tracked and got that) but no luck. Any ideas?
Everything else has been great aside from one other issue I noticed which if you final all the magic or heart containers the rom crashes, as it doesn't look like it wants to go past 8.
Sadly this problem is not caused by the hack, but it's caused by your emulator loading a savefile from the original Zelda II.

When you patched the ROM you probably didn't change the name of the ROM, causing your emulator to load an existing savefile with the same name. That's causing your game to start with too many hearts and magic, and keys will not appear in the correct spot.
Only solution to this is changing the name of your ROM to something like Z2AmidasCurse.nes, and start the game again from the start. The emulator will create a new savefile that way. You will notice when you start a new game you have 3 hearts and 2 magic containers.
This is why the ReadMe mentions to change the name of your ROM after patching, to make sure your emulator doesn't load an existing Z2 savefile.