Landstalker is a gem on the genesis.Though i wouldn't call it perfect due to it's isometric view,it did make platforming tricky.
Difficult platforming and hard puzzles are what make the game so good in my view. Most of the platforming, while difficult, is straightforward once you understand the engine a little bit (though there are some intentionally misleading spots - I believe the game engine was called the Illusion Engine or something!).
The split-second timing and execution of the puzzles in the game put Landstalker in a league of its own when it comes to puzzles - far outstripping Zelda's "light the torch" variety (and don't get me wrong, I love Zelda games).
Light Crusader is similar, and unfortunately overlooked for not being "Treasure enough" for a Treasure game. It's not as good as Landstalker but a very good game in its own right.