I only recently finished La-Mulana, Nigoro's "archaeological ruin exploration action game."
It tried its damnedest to make me quit at every turn; with its obtuse puzzles and tricky platforming, I don't feel it's hyperbole to say it's the most difficult game I've ever played. But underneath all the punishment was a memorable metroidvania in an enjoyable historic (and a delicious soundtrack).
We've heard that the La-Mulana 2 will be more intuitive than its predecessor without sacrificing the series' trademark difficulty. At PAX Prime, I had some hands-on time with the sequel that seems to confirm this, but I fear I still might need to rely on a walkthrough to navigate this maze.