The Good: Awesome controls; beautiful graphics for GBC; surprisingly dynamic music, even by GBA standards; impressive length and replayability; plenty of enjoyable sidequests and minigames; a relatively unique and enjoyable story; plenty of new game mechanics such as the rings, seeds, and riding three animals; link system works perfectly.
The Bad: The games came out so late in the GBC's life; it's incredibly difficult to deal with rings and getting the ones you want; it takes a whole lot of effort just to get the level two sword; after a certain point you can only ride one animal; most kids didn't have £60 for the two games (to get the real ending) and £100 for a GBA.
The Oracles arrived in 2001 for GBC. Problem was, the GBA soon eclipsed the system they were designed for.
But despite the awful timing, the games turned out really, really impressive. Unexpectedly so, even, because these are the first Zelda games not totally designed by Nintendo. Capcom handled the majority of development, in fact, but Nintendo devs (including Shigeru Miyamoto) watched over the process to make sure the games followed in the spirit and 'chronology' of the story.
Yet they needn't have worried; Capcom really pulled some amazing work out of nowhere for these two gems.
The story of Seasons is that General Onox captures Din, the Oracle of Seasons (and Goddess of Power) to destroy the world, by throwing the seasons out of whack. Ages has Veran capture Nayru, Oracle of Ages and Goddess of Wisdom to mess with time.
But both are parts of the grand plan of Twinrova, the mother(s) of Ganon, who want him resurrected, now that a different Link (presumably) killed him in a past game.
It's an odd story, but it's fitting, deep, and you'll quickly get caught up in exploring two lands that aren't Hyrule (not the norm in Zelda games). So the story's great, and their are plenty of fun characters to interact with.
But that's not all the good stuff to the game, of course. Otherwise it wouldn't be carrying the impressive 9.5 I gave it. The controls, too, are tight. They're similar to Link's Awakening (if it ain't broke don't fix it), but the menus are much more efficient and easier to navigate. Plus, you can save without going back to the menu, an important factor nowadays.
Now in game, the graphics are simply some of the best I've seen on a GBC. Pokemon Crystal is probably its only competitor. It's pretty clear an old NGB couldn't have handled this stuff.
The music pipes from the tiny little system (the GBC or GBA, whichever you're using) loud, clear, and beautiful. Beautiful for MIDI anyway... But that's to be expected.
Each game is somewhere between ten and twenty hours, maybe even thirty if you go and collect every single ring, heart piece, item, handle the trading sequence... all that stuff. And there's another game that leads right off the other to go play, too. So it's well worth your money to invest in both games.
And if you're willing to stick it out, all sixteen levels and the real ending are well worth seeing, in both games combined. The Zelda faithful in particular will love the conclusion to the games, and might pick up on the hint that the games are prequels to Link's Awakening (Link sails away at the end of the second game you play). In fact, there aren't many flaws to be had from these two immensely underestimated Zeldas (and you wouldn't think Zelda would be underestimated, either).
So what is wrong? As said, the release date was about as awful as the timing of most of the Metroid games; they just really got screwed in terms of time and opportunity. It's too bad that they couldn't get the games released earlier, or maybe update them for GBA graphics (though that would've admittedly taken some time).
But in terms of gameplay, the two have just minor little flaws. First, when you find a ring or a place to plant a seed to get a ring that grows from it (weird, I know), you have no idea what you'll get. This makes it hard to handle the ring system, and it's in fact far too unwieldy to rely on.
Additionally, both games have extremely long trading sequences. This means you'll have to get the Noble Sword after much toil and hardship in both games, even if you send your clear data to the second game. It's almost not worth it, but Onox and Ganon (yeah... he's the final boss, I'll just not bother with spoiler warnings) are nearly impossible without the Noble or Master Sword.
So here's what I'm saying: the game's aren't flawless, but they're damn close. If you love retro games and especially if you don't mind the fact the game's played on a tiny screen (and, for that matter, if you have a GBA/ SP, since DS's don't support the games), pick these up. They're certainly worthy investments now, being only £5-10. Just remember DS's don't play them. But to be honest, they improve on Link's Awakening in just about every way, and that's saying a lot.