Note/disclaimer - I played the version that was modified on Dec 6. From reading the thread, I see that some modifications were made prior to the Dec 6 qst file that I downloaded.
Despite some flaws (that are admittedly very minor, nitpicky, and subjective), I think if I had to vote for a single contest entry, this quest is my favorite so far (though I still have yet to play 7 or 8 of the entries). Prior to playing any of the 5th quest entries, I was keeping in mind Saffith's Antiquity quest as a sort of benchmark to which the entries could be measured. For me, now BigJoe's quest entry is the benchmark.
One glitch/bug to report: in level 9, three rooms west of Zelda's room, nothing happens after pushing the block.
Some minor suggestions:
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(1) I'm not sure that you needed to modify the overworld screen that contains level 5. On the plus side, it's a nice touch that the white level color matches its overworld entrance screen.
(2) It's possible to get stuck on level 8's boss if you run out of bombs. Perhaps a one-way walk-through wall (on the left side of the room) would be appropriate.
(3) I went hunting for the magic sword midway through level 6, simply because I felt I should have had it by that point. I'm wondering if it might be a good idea to have a "secrets where fairies don't live" message, though perhaps that gives too much information away. Were you to do so, I don't think it gives it away completely, since you already have a moblin at the Quest2-Level3 fountain that could function as a decoy.
(4) Why no boss key in level 9?
These are simply minor suggestions; I don't think that not implementing them detracts from the quest significantly. Just my two cents.
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Now my review of the quest:
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I love that you placed level 1 where you did. Having to make that trek with only 3 hearts is by no means a cakewalk, but it's very fair (imo) for a 5th quest. Given that quest entries shouldn't modify the overworld too drastically, it's difficult to challenge players with the possibility of dying in the overworld. For similar reasons, I was pleased with the placements of the white sword (not too hard to find) and blue ring (a bit harder to find, but there are only 2 possible places to bomb on that screen). Overall I like the balance of secrets in the overworld; some secrets are well hidden, though none are impossible or tedious to find.
Since there are no cheap (90) shield shops (unless I missed something), the blue ring shop also functions as the only place where you can buy the bait.
As others have attested, this quest is indeed one of the more difficult entries. Some of the bosses are tough (but let's be real, they are bosses). Despite the difficulty, the pacing is extremely well done. Acquiring key items (whistle, bracelet, ladder) gets you access to a HC. You'll likely want to have the white sword and blue ring for level 3, and the magic sword for level 6. You won't see a single wizzrobe until level 6. No dungeon is too difficult, though by level 5 you may want to be in the habit of bringing a red potion. The dungeons are not so difficult that you're required to visit multiple times with multiple red potions. In terms of size, the dungeons are for the most part larger than the dungeons in the 3rd and 4th quests, so your endurance will be tested.
This quest scores very high on the NES-authenticity metric (certainly the highest so far of the entries I've played). As is the case with the 3rd and 4th quests, no new items are introduced. The new enemies feel like logical extensions of the 2nd-3rd quests. As in the first and second quests, there are 3 dungeons with goriyas, 3 dungeons with darknuts, and 3 dungeons with wizzrobes (though level 9 is less constrained, just as in the 3rd quest). The colors of the dungeons match the enemies just as in the 1st-4th quests (wizzrobes in the gold-colored levels, goriyas in the blue-colored levels). Many of the dungeon rooms from the 1st-2nd quests are used in this quest, and in most (but not all - why?) instances where there was a block that could be pushed in the 1st-2nd quests, that same block gets pushed in BigJoe's quest (unless there are no blocks to be pushed). The dungeons have nice looking map shapes (and as in the 1st quest, I like that you called to attention to some shapes, such as the "eyes of zol" message).
I did miss a bomb upgrade (I found one in level 6), but assuming I didn't miss an upgrade earlier in the game, I think the player needs to have 12 bombs in order to explore level 5. There are a lot of bombable walls, and the map isn't provided until well into the depths of that dungeon.
I wasn't thrilled with having to blow the whistle within the later dungeons, but thankfully, this feature is used sparingly (three times I think). Although there's no message indicating that you should use your whistle (until level 9, unless I missed an earlier message), in your defense, it wasn't too difficult to deduce when to first use it in level 7. Because your previous dungeons are well designed with secrets and items hidden behind locked doors, a lightbulb should go off when a locked door leads to an ostensible dead-end in level 7. However, after seeing this feature for the first time, I became slightly paranoid that I might miss something if I wasn't diligent about always blowing the whistle, and that wasn't a good feeling.
Level 8 is well hidden in the overworld. Upon entering, I was slightly relieved to see the goriya enemy groups. While this dungeon is easier (imo) than levels 6 and 7 (the final goriya dungeon being a nice throwback to the first and second quests), it's thankfully not easy in an absolute sense, though most enemies can be stunned by the boomerang. The rooms with several shooting stalfos can be dangerous, but fortunately we've already had practice with them in level 4.
From reading the earlier posts in this thread, it seems that level 9 was previously much harder than the version I played (downloaded on Dec 6). I found the difficulty of the version I played to be appropriate, perhaps on par with level 9 of the 3rd quest (though I might say that Alphadawg's level 9 is slightly harder). Much like Alphadawg's level 9, you'll fight goriyas, darknuts, and wizzrobes, though in this quest you'll face green and brown versions (though not always 8 enemies with 10 statues to a room as in Alphadawg's level 9...a room with five green wizzrobes is plenty to handle here). As in the 1st-3rd quests, the map is huge, the silver arrow and red ring are well hidden but fun to find, and there's a tough patra fight immediately preceding the final boss.
Overall, this quest feels to be a very worthy successor to the 2nd, 3rd, and 4th quests. It is definitely fun to play. The NES limitations are implemented well, and the new enemies feel like logical extensions that Miyamoto might have implemented had he worked on a 5th quest with those same limitations. Secrets in the overworld are well hidden, though not impossible or tedious to find. The difficulty is certainly appropriate for a 5th quest entry, though at this point in the life cycle of ZC, I think that most players fancy themselves as darknut slayers, so the quest is certainly beatable (my death count was in the single digits). For me, of the quests I've played so far, this quest gets my vote as best contest entry.
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