You won't see a ton of new items here, and the new enemies generally seem well thought out and make for nice additions. I never found any defense rings during my run, and I'm unsure whether they don't exist, or I missed them. Regardless, I never really felt like I needed one outside of a couple of uncommonly hard-hitting enemies. If no rings exist, perhaps Roebloz ought to consider toning the damage of a few of the toughest enemies down a bit. There is also one boss that hits absurdly hard with a continue point in the fight ... without potions, I could see players getting stuck here, (though I expect that saving instead of continuing would escape the fight and put you back on the overworld). There's also a handful of odd decisions, such as apparent dead end screens with no purpose. All in all, there were a few eyebrow-raising moments, but nothing that substantially hampered my enjoyment.
Recommended if you enjoy the original Zelda without a ton of complications.
Edit:
Turns out I was wrong ... The quest veers into the really bad kind of difficulty at the tail end of the level. There's also some frustrating bugs in level 9 that resulted in me having to F6 to the beginning of the level, and I ended up cheating to win against the final boss, which is an enemy widely regarded as the most broken and unfair enemy in Zelda Classic. It's still a pretty solid quest, but I'm going to have to go with four stars instead of the five I was initially thinking, purely because of the reduction in quality at the very end of the game.After nearly completing level 9, it's safe to say my opinion on the quest isn't going to change, so I feel comfortable with writing this review.