BATTLE OF OLYMPUS / Broderbund / NES
The Battle of Olympus is obviously cribbing from Zelda II in visual and gameplay style, but in terms of structure it's really more like Rygar than anything else. You're dropped into the non-linear world of ancient Greece, and from bits of advice given by townspeople and cave-dwellers here and there, you have to figure out in what order to go to what areas to get the new items, weapons and powers you need to proceed.
Talking to NPCs is absolutely unavoidable here in order to have any idea where you're supposed to be going and what you're supposed to be doing next; taking notes is also probably a really good idea. Thankfully, the localization is actually quite good and the townspeople's advice doesn't have to be deciphered from moon language a la Castlevania 2; often they tell you exactly what you need to do, it's just a matter of figuring out how to get there, as the overall game world is a touch mazey.
The most enjoyable quality of the game is the graphical work; by NES standards, the background detail and use of color is well above average, maybe some of the best on the system. The music is a little spazzy and overly repetitive, unfortunately. The gameplay is a close second, being a solid imitiation of Zelda 2, if not featuring the entire robust move set that Link has. That's compensated for, however, by level design in general just being less annoying.
The game is bogged down by a few irritiating issues, however. A little bit into the game, you get an upgrade that actually causes your shield to function. However, projectiles still tend to sneak over the top of it even when it looks like they really shouldn't. The immediate purpose of the shield upgrade is to defeat an arrow-shooting Medusa boss; however, I found the blocking so unreliable that I ended up just having to bum-rush her while jumping and hope for the best, reloading a couple of times until the strategy actually (barely) worked. At first you have no need to grind for currency, but around the midpoint of the game you suddenly need to buy some very expensive items with no recourse but to grind enemies until they drop enough olives and snakeskins. There's also eventually a couple of "kneel by the cliff" puzzles where you have to jump in a completely counterintuitive spot to find a door, or even better, throw yourself down an otherwise unremarkable pit to find an item.
Battle of Olympus is a recommendation with some reservations, chiefly because it shows off how nice the NES is capable of looking. As the whole NES oeuvre of Metroidvania-esque games goes, I feel it's one of the better ones ... but there's few in the field that are actually worth playing anyway, so that's not much of a prize. On the whole, though, I'd say it's pretty good, barring a few mild to moderate annoyances.