The other night after completing the first quest I noticed that all the end credit text was all over the place and very glitched. It didn't stop any thing. But seemed a good idea to mention it. Now on to the second quest!
EDIT;
Found a minor GFX glitch in screen with the fairy & pond where LVL5 originally was. The trees on each side of the pond are half tree, half cabin. This also happens on the screen where lvl 3 is(where lvl 2 originally was).
Then a few screens to the left of the waterfall where the white sword was, there is a bomb cave near the stairway but Link is unable to cross to enter. Is the ladder trigger for that screen set?
On the screen where lvl 3 was originally, the left path transitions to a brown forrest area where Link is stuck in a row of trees. The left path should be blocked off or the trees have a path open.
Lvl 4's map is glitched on the left side. There is also a room in the upper map area where the shimmering snakes look like shimmering mummies that glitch into something else for half of their frame set. Also, the room with the 2 headed Gleeock never opens the shutter doors when the Gleeock is gone, forcing a reset. Gleeock returns even after the reset making the room unpassable.
Lvl 1 also has the glitched map on the left side. It might be easier to move the heart container gauge back to the right side, maybe? In the room that has the transfer stairs does not open the shutter door to get back out. I went back in after getting the fairy to see if I missed anything and got stuck in that room.
Lvl 3 also has a glitched map and is a dead end with no way to proceed. There are also two entrances.
Lvl 7 has a glitched map but is otherwise fine.
Lvl 5 has a glitched map. The second set of transfer stairs have a bow but it is unreachable. Additionally there is more than one entrance to lvl 5. If you reenter there is no way out as exiting transitions to another room. Requires save & continue.
This is as far as I've gotten so far. I'll chime in later with anything else I find.
BTW, Don't give up on this, it looks very good and is going to be one of the best LOZ1 hacks out there once finished!